I have almost 20GB of "other" files on my iPhone 5S 64GB (which I have only had for four months), and it seems to keep growing. (I keep needing to delete files/apps from my phone to free up space, even if I am not adding much apart from a photo now and then.) I tried to run PhoneClean 3, but the quick clean didn't remove much, and the deep clean failed because of an "unusually complicated structure" on my phone. I would like to back up everything, clean the phone, and reinstall, but am unable to since my laptop doesn't have enough space for the backup. Is there a way to backup the iPhone to an external drive? Also, what other options do I have? I am interested in deleting most or all of the 20GB of other files, not just a few files here and there.