I would suggest having a donation option, more people are likely to spend money that way - less likely to get annoyed with your app.
Wait for the API to arrive and you'll be a lot better off developing the app
Thanks for the suggestion, /u/cunt.
Couldn't resist ;)
oh. my. god. when I was trying to select a username, this was exactly the kind of thing I was trying to find in my mind, instead I gave up. I am severely disappointed in myself.