I have this really good idea but please don't tell anyone. I want to make a fart application that farts when you press a button. I don't think anyone has made one yet.... oh... wait... lol.
Anyways no, I think there are plenty of apps out there, however there are always new ideas that people haven't thought of, until people find it and go "holy crap I can't believe I haven't thought of this". And then there's the applications that are modified and changed and made better (or worse). Not innovative, but still progresses things.