iPhone says there is not enough space/room to download an app, but there is Cannot Download
There is not enough available storage to download &quot;&lt;APP&gt;&quot;. You can manage your storage in Settings.

My brother gets this error message when we go to install a large app from the App Store. He has 1.2 GB free and the app is ~600 MB. Why is it doing giving us this error, and do I really need to clear more space? What else could be wrong?
The size listed on the App Store is for the actual IPA, which is nothing but a zip file, the contents of which are compressed. The install size can be double or even more, depending on the app and its contents.