STOCK PLEDGE AND ESCROW AGREEMENT

Exhibit 10.02

STOCK PLEDGE AND ESCROW AGREEMENT

THIS STOCK PLEDGE AND ESCROW AGREEMENT (this “Agreement”), dated as of April 1,, 2010, is made by and between AMHN, INC., a Utah corporation, (“Pledgor”), and SEATAC DIGITAL RESOURCES, INC., a Delaware corporation (“Seatac”). All capitalized terms used herein without definitions shall have the respective meanings ascribed to them in the Note Purchase Agreement of even date herewith by and between Seatac and Pledgor (the “Note Purchase Agreement”).

RECITALS

A. Pledgor is the legal and beneficial owner of the Pledged Interests (as hereinafter defined) hereby pledged by Pledgor.

B. Pursuant to a Note Purchase Agreement and a 4% Secured Promissory Note due June 30, 2010 issued by Pledgor to Seatac (as amended or modified from time to time, the “Note”), Seatac has made an $800,000 loan (the “Loan”) to Pledgor.

C. In order to secure the full and prompt payment when due (whether at the stated maturity, by acceleration or otherwise) of the Note and to secure all of the Company’s Obligations (as hereinafter defined) to Seatac, the Pledgor has agreed to irrevocably pledge to Seatac the Pledged Interests (as hereinafter defined).

D. It is a condition precedent to Seatac making the Loan that Pledgor execute and deliver to Seatac a stock pledge and escrow agreement in the form hereof. This is the Stock Pledge and Escrow Agreement referred to in the Note Purchase Agreement.

AGREEMENTS

In consideration of the recitals and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, Pledgor hereby agrees with Seatac, as follows:

1. Defined Terms. All terms defined in the Uniform Commercial Code in effect from time to time in the State and used herein shall have the same definitions herein as specified therein; provided, however, if a term is defined in Article 9 of the Uniform Commercial Code of the State differently than in another Article of the Uniform Commercial Code of the State, the term has the meaning specified in Article 9. As used herein, the following terms have the following meanings:

“Code” means the Uniform Commercial Code from time to time in effect in the State.

“Collateral” means the Pledged Interests and all Proceeds.

“Issuer” means each issuer of Pledged Interests listed on Schedule 1 hereto.

“Obligations” shall mean (a) the principal of, and interest on, the Note, and any renewal, extension or refinancing thereof; (b) all debts, liabilities, obligations, covenants and agreements of Pledgor contained in the Transaction Documents; and (c) any and all other debts, liabilities and obligations of Pledgor to Seatac.

“Pledged Interests” means the membership interests, shares of capital stock or other equity interests listed on Schedule 1 hereto, together with all membership or stock certificates, options or rights of any nature whatsoever that may be issued or granted by Issuer to Pledgor in respect of the Pledged Interests while this Agreement is in effect.

“Proceeds” means all “proceeds” as such term is defined in Section 9-102 of the Code and shall include, without limitation, all dividends or other income from the Pledged Interests, collections thereon, or distributions with respect thereto.

“Securities Act” means the Securities Act of 1933, as amended.

“State” means the State of California.

2. Pledge; Grant of Security Interest. Pledgor hereby grants to Seatac a first priority security interest in the Collateral as security for the prompt and complete performance of all of the Obligations. Pledgor hereby asserts that this Agreement is not in conflict with the bylaws of the Company.

3. Escrow of Pledged Interests. Simultaneously with the execution of the Transaction Documents, the Pledgor hereby delivers to Smith & Associates (“the Escrow Agent”) certificates representing the Pledged Interests, together with duly executed stock powers or other appropriate transfer documents executed in blank by the Pledgor. Such stock certificates shall be held by the Escrow Agent until released pursuant to the terms of Section 4 below.

4. Release of Pledged Interests from Escrow. Upon the payment of all amounts due to Seatac under the Note in accordance with its terms, Seatac and Pledgor shall jointly notify the Escrow Agent to such effect in writing. Upon receipt of such written notice, the Escrow Agent shall return to the Pledgor the certificates representing the Pledged Interests, whereupon any and all rights of Seatac in the Pledged Interests shall be terminated. Notwithstanding anything to the contrary contained herein, upon the payment of all amounts due to Seatac under the Note in accordance with its terms, Seatac’s security interest and rights in and to the Pledged Interests shall terminate.

5. Concerning the Escrow Agent.

(a) Disputes. If any dispute arises with respect to the Pledged Interests or this Agreement, or if any disagreements arise among the parties hereto with respect to the interpretation of this Agreement, or concerning their rights and obligations hereunder, or the propriety of any action contemplated by the Escrow Agent hereunder, or if the Escrow Agent in good faith is in doubt what action should be taken hereunder, the Escrow Agent shall not be obligated to resolve the dispute or disagreement or to release the Pledged Interests, but may commence an action in the nature of an interpleader and seek to deposit the Pledged Interests with a court of competent jurisdiction, and thereby be discharged from any further duty or obligation with respect to the Pledged Interests. Upon the interpleader action being properly brought, all parties being joined and the Pledged Interests being deposited with the court, the Escrow Agent shall be discharged from any obligations accruing thereafter with respect to the Pledged Interests. The Escrow Agent, in its sole discretion, may, in lieu of filing such action in interpleader, elect to cease performance under this Agreement in connection with any instruction or notice received regarding the release of the Pledged Interests until the Escrow Agent has received: (a) a written notice of resolution of such dispute or disagreement signed by the parties to such dispute or disagreement, or (b) a certified copy of a final judgment of a court of competent jurisdiction, provided, however, that a certified copy of a final judgment shall serve as a valid determination only if the time for appeal has expired and no appeal has been perfected or all appeals have been exhausted or no right of appeal exists.

2

(b) Extent of Duties of Escrow Agent.

(i) The Escrow Agent shall be responsible only for performance of its duties as specified in this Agreement, and no implied covenants, duties or obligations shall bind or be enforceable against the Escrow Agent. The Escrow Agent shall not be liable to any person or entity for any act or failure to act unless due to the Escrow Agent’s willful misconduct.

(ii) Subject to Section 5(b)(i) hereof, the Escrow Agent shall not be liable for any action taken or omitted by it, or any action suffered by it to be taken or administered in good faith and in the exercise of its own best judgment, and may rely conclusively and shall be protected in acting in good faith upon any order, notice, demand, certificate, advice of counsel (including counsel selected by the Escrow Agent), statement, instrument, report or other document (not only as to its due execution and the validity and effectiveness thereof, but also as to the truth and acceptability of any information therein contained) which is reasonably believed by the Escrow Agent to be genuine and to be signed by the proper person or persons.

(iii) Pledgor and Seatac shall indemnify the Escrow Agent and hold it harmless from any and all claims, liabilities, damages, losses, or any other expenses, fees or charges of any character or nature, which it may incur or with which it may be threatened by reason of its acting as Escrow Agent under this Agreement, including but not limited to any and all damages, costs, losses and other expenses, including reasonable attorneys’ fees and expenses, resulting from or arising in connection with any action, suit, or proceeding incident to the Escrow Agent’s acting as such hereunder, unless such action, suit or proceeding relates to the Escrow Agent’s willful misconduct.

(c) Conflict Waiver. THE PLEDGOR HEREBY ACKNOWLEDGES THAT THE ESCROW AGENT IS ACTING AS LEGAL COUNSEL TO SEATAC IN CONNECTION WITH THE TRANSACTIONS CONTEMPLATED AND REFERRED TO HEREIN. THE PLEDGOR AGREES THAT IN THE EVENT OF ANY DISPUTE ARISING IN CONNECTION WITH THIS AGREEMENT OR OTHERWISE IN CONNECTION WITH ANY TRANSACTION OR AGREEMENT CONTEMPLATED AND REFERRED TO HEREIN, THE ESCROW AGENT SHALL BE PERMITTED TO CONTINUE TO REPRESENT SEATAC AND THE PLEDGOR WILL NOT SEEK TO DISQUALIFY SUCH COUNSEL AND WAIVES ANY OBJECTION PLEDGOR MIGHT HAVE WITH RESPECT TO THE ESCROW AGENT ACTING AS THE ESCROW AGENT PURSUANT TO THIS AGREEMENT AND LEGAL COUNSEL TO SEATAC.

6. Representations and Warranties. Pledgor represents and warrants that:

(a) all the shares of such Pledged Interests have been duly and validly issued and are fully paid and nonassessable;

(b) Pledgor is the record and beneficial owner of, and has good and marketable title to, such Pledged Interests, free of any and all liens or options in favor of, or claims of, any other person, except the security interest created by this Agreement; and

(c) upon either (i) the delivery to Seatac of the stock or membership interest certificates evidencing such Pledged Interests and the stock or membership interest powers or (ii) the filing of a financing statement listing Pledgor as debtor and Seatac as secured party and describing the Collateral, the security interest created by this Agreement will constitute a valid, perfected first priority security interest in the Collateral granted by Pledgor, enforceable in accordance with its terms against all creditors of Pledgor and any persons purporting to purchase any Collateral from Pledgor, except as

3

affected by bankruptcy, insolvency, fraudulent conveyance, reorganization, moratorium and other similar laws relating to or affecting creditors’ rights generally, general equitable principles (whether considered in a proceeding in equity or at law) and an implied covenant of good faith and fair dealing.

7. Covenants. Pledgor covenants and agrees with Seatac that, from and after the date of this Agreement until the Obligations are performed in full:

(a) If Pledgor shall, as a result of its ownership of any Pledged Interests, become entitled to receive or shall receive any stock or membership interest certificate (including, without limitation, any certificate representing a stock or membership interest dividend or a distribution in connection with any reclassification, increase or reduction of capital or any certificate issued in connection with any reorganization), option or rights, whether in addition to, in substitution of, as a conversion of, or in exchange for any shares of any Pledged Interests, or otherwise in respect thereof, Pledgor shall accept the same as the agent of Seatac, hold the same in trust for Seatac and deliver the same forthwith to Seatac in the exact form received, duly indorsed by Pledgor to Seatac, if required, together with an undated stock or membership interest power covering such certificate duly executed in blank by Pledgor, to be held by Seatac, subject to the terms hereof, as additional collateral security for the Obligations of Pledgor. Any property distributed to Pledgor upon or in respect of any Pledged Interests upon the liquidation, dissolution, recapitalization or reorganization of an Issuer, shall be delivered to Seatac as additional collateral security for the Obligations of Pledgor. If any property distributed in respect of any Pledged Interests shall be received by Pledgor while an Event of Default exists, Pledgor shall, until such property is delivered to Seatac, hold the property in trust for Seatac, segregated from other property of Pledgor, as additional collateral security for the Obligations of Pledgor.

(b) Without the prior written consent of Seatac, Pledgor shall not vote to enable, or take any other action to permit, an Issuer to issue any stock or membership interest or other equity securities of any nature or to issue any other securities convertible into or granting the right to purchase or exchange for any stock or membership interest or other equity securities of any nature of an Issuer, sell, assign, transfer, exchange, or otherwise dispose of, or grant any option with respect to, the Collateral, or create, incur or permit to exist any lien or option in favor of, or any claim of any person with respect to, any of the Collateral, or any interest therein, except for Pledgor and except for the security interests created by this Agreement. Pledgor will defend the right, title and interest of Seatac in and to the Collateral against the claims and demands of all persons whomsoever.

(c) At any time and from time to time, upon the written request of Seatac to Pledgor, and at its sole expense, Pledgor will promptly and duly execute and deliver such further instruments and documents and take such further actions as Seatac may reasonably request for the purposes of obtaining or preserving the full benefits of this Agreement and of the rights and powers herein granted. If any amount payable under or in connection with any of the Collateral shall be or become evidenced by any promissory note, other instrument or chattel paper, such note, instrument or chattel paper shall be immediately delivered to Seatac, duly endorsed in a manner satisfactory to Seatac, to be held as Collateral pursuant to this Agreement.

(d) Pledgor shall pay, and save Seatac harmless from, any and all liabilities with respect to, or resulting from any delay in paying, any and all stamp, excise, sales or other taxes which may be payable or determined to be payable with respect to any of the Collateral granted by Pledgor or in connection with any of the transactions contemplated by this Agreement.

(e) Pledgor covenants and agrees to comply with the requirements set forth in Articles VII and VIII of the Note Purchase Agreement.

4

8. Voting Rights. Unless an Event of Default shall have occurred and be continuing, and written notice that Seatac intends to exercise voting rights is given to Pledgor by Seatac, Pledgor shall be permitted to exercise all voting and related rights with respect to such Pledged Interests; provided, however, that no vote shall be cast or related right exercised or other action taken which, in the reasonable judgment of Seatac, would impair the Collateral or which would be inconsistent with or result in any violation of any provision of this Agreement.

9. Rights of Seatac. If an Event of Default shall occur and be continuing, Seatac shall have the right to have any or all shares of Pledged Interests registered in its name or the name of its nominee, and Seatac or its nominee may thereafter exercise all voting, related and other rights pertaining to such Pledged Interests at any meeting of members or shareholders of an Issuer or otherwise and any and all rights of conversion, exchange, subscription and any other rights, privileges or options pertaining to such Pledged Interests as if it were the absolute owner thereof (including, without limitation, the right to exchange at its discretion any and all of the Pledged Interests upon the merger, consolidation, reorganization, recapitalization or other fundamental change in the corporate or limited liability company structure of an Issuer, or upon the exercise by Pledgor or Seatac of any right, privilege or option pertaining to such Pledged Interests, and in connection therewith, the right to deposit and deliver any and all of such Pledged Interests with any committee, depositary, transfer agent, registrar or other designated agency upon such terms and conditions as Seatac may determine).

The rights of Seatac hereunder shall not be conditioned or contingent upon the pursuit by Seatac of any right or remedy against an Issuer or any obligor or against any other person which may be or become liable in respect of all or any part of the Obligations or against any collateral security therefor, guarantee thereof or right of offset with respect thereto. Seatac shall not be liable for any failure to demand, collect or realize upon all or any part of the Collateral or for any delay in doing so, nor shall Seatac be under any obligation to sell or otherwise dispose of any Collateral upon the request of Pledgor or any other person or to take any other action whatsoever with regard to the Collateral or any part thereof.

10. Remedies; Sale Proceeds.

(a) If an Event of Default shall occur and be continuing, Seatac may exercise, in addition to all other rights and remedies granted in this Agreement, all rights and remedies of a secured party under the Code as Seatac deems advisable. Without limiting the generality of the foregoing, Seatac, without demand of performance or other demand, presentment, protest, advertisement or notice of any kind (except any notice required by law referred to below) to or upon Pledgor, an Issuer, any obligor or any other person (all and each of which demands, defenses, advertisements and notices are hereby waived), may in such circumstances forthwith collect, receive, appropriate and realize upon the Collateral, or any part thereof, and/or may forthwith sell, assign, give option or options to purchase or otherwise dispose of and deliver the Collateral or any part thereof (or contract to do any of the foregoing), in one or more parcels at public or private sale or sales, in the over-the-counter market, at any exchange, broker’s board or office of Seatac or elsewhere upon such terms and conditions as it may deem advisable and at such prices as are commercially reasonable, for cash or on credit or for future delivery without assumption of any credit risk.

Seatac shall have the right upon any such public sale or sales, and, to the extent permitted by law, upon any such private sale or sales, to purchase the whole or any part of the Collateral so sold, free of any right or equity of redemption in Pledgor, which right or equity is hereby waived or released. If any notice of a proposed sale or other disposition of Collateral shall be required by law, such notice shall be deemed reasonable and proper if given at least ten (10) days before such sale or other disposition.

5

(b) Seatac shall apply any Proceeds from time to time held by it and the net proceeds of any such collection, recovery, receipt, appropriation, realization or sale, after deducting all costs and expenses of every kind incurred in respect thereof or incidental to the care or safekeeping of any of the Collateral or in any way relating to the Collateral or the rights of Seatac hereunder, including, without limitation, attorneys’ fees and disbursements of counsel (including in-house counsel) to Seatac, to the payment in whole or in part of the Obligations, as Seatac may otherwise decide, and only after such application and after the payment by Seatac of any other amount required by any provision of law, including, without limitation, Section 9-615(4)(a) of the Code, need Seatac account for the surplus, if any, to Pledgor. To the extent permitted by applicable law, Pledgor waives all claims, damages and demands it may acquire against Seatac arising out of the exercise by it of any rights hereunder, except such claims and damages arising out of the gross negligence or willful misconduct of Seatac. Pledgor shall remain liable for any deficiency if the proceeds of any sale or other disposition of Collateral are insufficient to pay the Obligations of Pledgor and the fees and disbursements of any attorneys employed by Seatac to collect such deficiency.

11. Private Sales.

(a) Pledgor recognizes that Seatac may be unable to effect a public sale of any or all the Pledged Interests, by reason of certain prohibitions contained in the Securities Act and applicable state securities laws or otherwise, and may be compelled to resort to one or more private sales thereof to a restricted group of purchasers which will be obliged to agree, among other things, to acquire such securities for their own account for investment and not with a view to the distribution or resale thereof. Pledgor acknowledges and agrees that any such private sale may result in prices and other terms less favorable than if such sale were a public sale and, notwithstanding such circumstances, agrees that any such private sale shall not be deemed to have been made in a commercially unreasonable manner solely by virtue of such private sale. Seatac shall be under no obligation to delay a sale of any of the Pledged Interests for the period of time necessary to permit the applicable Issuer thereof to register such securities for public sale under the Securities Act, or under applicable state securities laws, even if such Issuer would agree to do so.

(b) Pledgor further agrees to use its best efforts to do or cause to be done all such other acts as may be necessary to make such sale or sales of all or any portion of the Pledged Interests pursuant to this section valid and binding and in compliance with any and all other applicable requirements of law, except that Pledgor shall not be obligated to register the Pledged Interests under state or federal securities laws. Pledgor further agrees that a breach of any of the covenants contained in this Section will cause irreparable injury to Seatac, that Seatac has no adequate remedy at law in respect of such breach and, as a consequence, that each and every covenant contained in this Section 9 shall be specifically enforceable against Pledgor, and Pledgor hereby waives and agrees not to assert any defenses against an action for specific performance of such covenants except for a defense that no Event of Default has occurred.

12. Irrevocable Authorization and Instruction to Issuer. Pledgor hereby authorizes and instructs each Issuer of its Pledged Interests to comply with any instruction received by it from Seatac in writing that (a) states that an Event of Default exists and (b) is otherwise in accordance with the terms of this Agreement, without any other or further instructions from Pledgor, and Pledgor agrees that Issuer shall be fully protected in so complying.

13. Seatac’s Appointment as Attorney-in-Fact. Pledgor hereby irrevocably constitutes and appoints Seatac and any officer or agent of Seatac, with full power of substitution, as its true and lawful attorney-in-fact with full irrevocable power and authority in the place and stead of Pledgor and in the name of Pledgor or in the name of Seatac, from time to time in the discretion of Seatac so long as an

6

Event of Default exists, for the purpose of carrying out the terms of this Agreement, to take any and all appropriate action and to execute any and all documents and instruments which may be necessary or desirable to accomplish the purposes of this Agreement, including, without limitation, any financing statements, endorsements, assignments or other instruments of transfer.

Pledgor hereby ratifies all that said attorneys shall lawfully do or cause to be done pursuant to the power of attorney granted in this Section 13. All powers, authorizations and agencies contained in this Agreement are coupled with an interest and are irrevocable until the Obligations are performed in full.

14. Duty of Seatac. The sole duty of Seatac with respect to the custody, safekeeping and physical preservation of the Collateral in its possession, under Section 9-207 of the Code or otherwise, shall be to deal with it in the same manner as Seatac deals with similar securities and property for its own account. Neither Seatac nor any of its directors, officers, employees or agents shall be liable for failure to demand, collect or realize upon any of the Collateral or for any delay in doing so or shall be under any obligation to sell or otherwise dispose of any Collateral upon the request of Pledgor or any other person or to take any other action whatsoever with regard to the Collateral or any part thereof.

15. Filing Financing Statements. Pledgor authorizes Seatac to file financing statements with respect to the Collateral without the signature of Pledgor in such form and in such filing offices as Seatac reasonably determines appropriate to perfect the security interests of Seatac under this Agreement.

16. Notices. All notices, requests and demands to or upon Seatac, Pledgor or Issuer (to be delivered care of the Pledgor) to be effective shall be delivered in the manner set forth in Section 12.6 of the Note Purchase Agreement.

17. Severability. Any provision of this Agreement which is prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to the extent of such prohibition or unenforceability without invalidating the remaining provisions hereof, and any such prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable such provision in any other jurisdiction.

18. Amendments in Writing; No Waiver; Cumulative Remedies. Seatac shall not by any act (except by a written instrument signed by Seatac), delay, indulgence, omission or otherwise be deemed to have waived any right or remedy hereunder or to have acquiesced in any Event of Default or in any breach of any of the terms and conditions hereof. No failure to exercise, nor any delay in exercising, on the part of Seatac, any right, power or privilege hereunder shall operate as a waiver thereof. No single or partial exercise of any right, power or privilege hereunder shall preclude any other or further exercise thereof or the exercise of any other right, power or privilege. A waiver by Seatac of any right or remedy hereunder on any one occasion shall not be construed as a bar to any right or remedy which Seatac would otherwise have on any future occasion. The rights and remedies herein provided are cumulative, may be exercised singly or concurrently and are not exclusive of any other rights or remedies provided by law.

19. Section Headings. The section headings used in this Agreement are for convenience of reference only and are not to affect the construction hereof or be taken into consideration in the interpretation hereof.

20. Successors and Assigns. This Agreement shall be binding upon the successors and assigns of Pledgor and shall inure to the benefit of Seatac and their successors and assigns.

21. Governing Law. THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF CALIFORNIA WITHOUT GIVING EFFECT TO ITS CONFLICTS OF LAW PROVISIONS.

7

22. Consent to Jurisdiction and Venue. All actions or proceedings brought against Pledgor with respect to this Agreement may be brought only in courts of the State of California located in Los Angeles County and Pledgor consents to the jurisdiction of such courts. Pledgor waives any objection it may now or hereafter have to the venue of any such court and any right it may have now or hereafter have to claim that any such action or proceeding is in an inconvenient court.

23. WAIVER OF RIGHT TO JURY TRIAL. PLEDGOR AND SEATAC ACKNOWLEDGE AND AGREE THAT ANY CONTROVERSY WHICH MAY ARISE UNDER THIS PLEDGE AGREEMENT WOULD BE BASED UPON DIFFICULT AND COMPLEX ISSUES AND, THEREFORE, PLEDGOR AND SEATAC AGREE THAT ANY LAWSUIT ARISING OUT OF ANY SUCH CONTROVERSY SHALL BE TRIED IN A COURT OF COMPETENT JURISDICTION BY A JUDGE SITTING WITHOUT A JURY.

(Signature page follows)

8

IN WITNESS WHEREOF, the undersigned has caused this Pledge and Escrow Agreement to be duly executed and delivered as of the date first above written.

Signature Page to Pledge Agreement

SCHEDULE 1

TO PLEDGE AGREEMENT

DESCRIPTION OF PLEDGED INTERESTS

ACKNOWLEDGMENT AND CONSENT

The undersigned is the Issuer referred to in the foregoing Stock Pledge and Escrow Agreement and hereby acknowledges receipt of a copy of the Stock Pledge and Escrow Agreement, dated as of April 1, 2010, made by Pledgor (as defined therein) in favor of Seatac (as defined therein) (as amended, supplemented or otherwise modified from time to time, the “Pledge Agreement”). The undersigned agrees for the benefit of Seatac as follows:

1. The undersigned will be bound by the terms of the Pledge Agreement and will comply with such terms insofar as such terms are applicable to the undersigned.

2. The undersigned will notify Seatac promptly in writing of the occurrence of any of the events described in paragraph 5(a) of the Pledge Agreement.

Acknowledgment and Consent to Pledge Agreement