Who knows, but Google made the Maps app first for all other phones, so I suspect they did the iPhone version as well... especially when they started including their cell tower location capabilities that other phones had first.Apple made the YouTube and Google Maps apps for the phone, not Google.
+1If Apple wants to not care about Google's use of the proximity sensor in the new version of Google Mobile App then fine - I'm all for that - but they need to give all developers a level playing field and get rid of the Mysterious Black Box of Approvals.
That would be true for BREW based dumb phone apps.... it seems like the iPhone is much more accessible to small developers than most cell phones or PDAs.
But Blackberries are especially cheap and easy to develop for. So are WM phones, and most Java enabled phones. Even better for the Java based ones is that you can develop apps using PCs, Macs, UNIX boxes, whatever.
Heck, there are tiny BASIC-like interpreters for many smartphones, so just about anyone can write an app in their home for their own use, or give it to friends. Apple forbids such interpreters, so that they can control EVERY app.