Could you please remove the 'sign in with facebook' option? or at least allow other methods of authentication (I prefer Google but ideally people should have the options).
As an avid traveler, I've been relying on friends' friends wherever I go. I could see your app flying!
Being a plaintiff doesn't always mean you're the one suing. It could be an appeals court case where the positions are reversed. Also, you could sue an NPE in order to invalidate their patent(s), or to seek an injunction.
I have never sold (or bought) a web app before, but I have had to value various different types of assets due to my job. The most common valuation technique would be to use the Discounted Cash Flow model. In short, you project your pre-tax cash flow for say the next 10 years, and discount them at the required return which the investors are looking for. This rate is determined by a multitude of factors, such as the stability of your business model, target market, etc.
Then at the end of your projection, you simulate a sale of your business by 'capping' it at a certain rate. Then you add this terminal value to the sum of all the discounted cash flows calculated above, you have the total value for your business.
Of course in hi-tech sector things fluctuate too much too quickly. But the model should be the same, you just have to adjust your discount rate and terminal capitalization rate to account for those fluctuations.
Will give this one a try.