With iOS7, Apple has upped the cap for app downloads over cellular to 100MB, meaning that if you carelessly hit “update all” for your apps when you’re out of the house, and you have a bunch of game updates pending for your iPhone, then you could potentially burn through your entire month’s bandwidth allowance in one go.
The current (or previous, depending on whether you updated to iOS7 yet) was/is 50MB, and was originally 10MB with the iPhone 3G. Before that, all app downloads were Wi-Fi-only. This new limit makes sense I guess, but as someone who has actually been stung by accidental updates over cellular (leaving me stranded without internet for several days), it’d be nice to have some control over it. Then again, what do I know?
Source: Apple Insider