dduck

Personally I would run a grep to find if someone has already been doing that. This is also difficult to use in forgotten password forms.

I am not sure m4a format can be played on Android devices.

I once got into the iOS app store in 2 hours, it was the first time I was sending an app to the store and it was in 2012. So don't count on anything. App Store may come out and ruin all your plans.