I would consider explaining to her the following: 1. that the time to have negotiated that deal would have been prior to your doing all the work; 2. now that yo

I would consider explaining to her the following: 1. that the time to have negotiated that deal would have been prior to your doing all the work; 2. now that you have done it and have no obligation to sign this, she can't do anything with the work product without running the risk of your suing her for 50% ownership, which you would certainly do if anything came of it (and by the way, don't post the app, transfer the code, etc) 3. that you are open to any reasonable offer and will sign IP/tech assignment rights, post app, share code, etc. as appropriate if you reach agreement; 4. That she might want to consider this a business lesson of the sort they apparently don't teach in business school, and you won't charge her anything extra for it.... * = i'm assuming US or US-type legal framework here (edited for formatting only)