When you update an app from the Mac App Store, you don’t always have to download the entire app. I’m not sure how this works, but I see many updates to be only a few MB; even Apple app updates are much smaller than the size of their full apps (for apps like Pages, Keynote, etc.).
But this isn’t the case with iOS apps. There’s no reason that I should have to download this much data to update this app:
When the update is merely for minor bug fixes:
Since a lot of people update iOS apps on their iPhones or iPads, they may mistakenly initiate updates when using cellular data, and be surprised by how much data is used. (The App Store app does specify the size of an update, but I’m sure a lot of people ignore it.)
I’m also a bit surprised that the update is larger on my iPad than it is via iTunes on my Mac:
This could just be the way that Apple calculates space on iOS devices versus Macs. But the two should be the same.
In any case, there’s no need to force users to update entire apps. There are ways to provide incremental updates, and Apple should do this for iOS. Some of us have bandwidth caps, and large apps like this shouldn’t have to be fully downloading just for “minor bug fixes.”
Update: Apparently, the app store is supposed to do this automatically. It’s not clear why this doesn’t occur with all apps.