Is this a free app? If not, you might want to check your platform of choice assumption – while there may be a large base of android smartphone users, they convert at much lower rates into paying customers than do iPhone/iOS device users.
But even before that, if you lack development experience, and are targeting a prototype stage app, I'd strongly recommend a (cheaper, multi platform) web app for your first iteration… It'll still be clear enough to use for developer and investor recruitment, with a faster time to market.
