I'd like to design a ipad/iphone app that organizes and displays public domain fiddle sheet music.
I'd like a way to maintain the library of tunes (pdf files) via a web interface/backend.
A free version that only displays 20 tunes.
A paid version which displays the complete library.
As an example, look at the app called ireal book.
This app only displays the chord changes, not the actual sheet music
But i like how it organizes the titles, and also allows one to transpose the key.