I have a problem with my Facebook app where the App Store says it's supposed to be 59.6 MB but when it downloads (and I haven't open it yet), it's 167 MB.
Ironically, I wrote a blog post about how apps like Facebook and Messenger cache images and posts, which takes up space, and can only be stopped (without jailbreaking) by deleting and reinstalling the app. This is because when you delete the app, it also deletes 'Documents and Data' (including cached data).
I conclude that for whatever reason, the cached data is not being deleted, but I could be wrong.
Does anybody know how to fix this?
Best Answer
Apps are compressed when you download them. When you have downloaded them, they are uncompressed on your phone.
Therefore you'll see that the App Store states a smaller size, which is the size you have to download - and the phone states a different, larger size, which is the space it takes up on the disk inside the phone.
See for example:
http://en.wikipedia.org/wiki/.ipa_(file_extension)
It states clearly that apps are delivered as .ipa files from the App Store, and that such a file is compressed (zipped).