My apps are using 3.7GB of storage on my iPad, how can I check which app is using what amount?

Solution 1:

On iTunes itself, on the App section of your Library (top section in the left side navigation bar) you can see how big Apps are by switching to List view (iTunes menu bar -> View -> As List).

Solution 2:

On the iPad If you go to Settings -> General -> Usage and a list of your apps will pop up right there, along with the amount of storage that they're taking up.