I need an android and iOS app built with Xamarin, c#, that allows the user to take a funny picture of their kids, with their face in a frame, something like a fair photo board (see attached examples). After taking the photo, it needs to save it to users' phone and save it to a database thru an API that I will provide. Also user needs to be able to post the photo on facebook and twitter.
Functions: Login-register (through a webservice that I will provide), browsing photo board samples to pick what they like, seeing the camera preview overlaid by the board to take photo. I also need it to work from database, meaning that I will need to be able to add new photo boards anytime to the database.