Apple caps 3g app downloads at 30mb I think. Any bigger than that and you need to use wifi or sync via iTunes.
It would be nice if Google would implement something like this for Android. I didn't even know about this limitation until today ( I'm an iPhone user/developer).
Android App store warns you that you are about to start a large download via 3G and asks if you're sure you want to do so. Personally I find that a much better approach. Apple doesn't know the details of my contract and if I want to download 70 (or 170)MB over 3G, surely that's my prerogative and why should my phone stop me?
I have unlimited 3G data plan on my iPad and it always hated that Apple won't let me update some apps until I'm near WiFi spot... until I bought Galaxy Nexus inserted SIM from my phone with limited data plan and it exceeded my capped data plan in the first hour (OS updates).
It would be nice if Google would implement something like this for Android. I didn't even know about this limitation until today ( I'm an iPhone user/developer).