I was thinking about mobile apps and selling them... but I thought it might be a good idea to simply advertise bitcoin for the free version of the app. what do you guys think?
What do you mean with "to advertise bitcoin in the free version"?
Use bitcoin advertisement/publisher networks like CoinURL? If so, there are better USD alternatives for mobile out there.
If you want to ask money for paid version with BTC - I think that's impossible/not allowed at least in the Apple App store.
I don't think The bitcoin foundation would pay for ads in your app either, why would they, the ROI in that would be pretty bad probably and mainstream media is already reporting on Bitcoin weekly.
Furthermore, I know that most popular bitcoin explanation video was made by some people from the forums that got money that was raised on the forums for it.
