I have a theory that Apple designs iOS in a way that it will not start clearing up app cache, temp files, junk, etc. until there is absolutely little or no space left for one reason: to get you to think that you should purcha$e the 64gb or 128gb model when the next iPad Air come$ out. I've used CCleaner which was just recently available for iPad and I've managed to clean up 2-3 gb of disk space. There are apps that are just flat out cache hogs (like Instagram and Facebook). These days, 32gb is a sweet spot. But if you don't watch your storage space buildup and do something about it (like CCleaner or up PhoneClean), those junk files or piled up cached data from apps will just sit there and do nothing in your iPad.