I just installed ccleaner for my Fire Tablet 10 (9th gen) and so far it is working more quickly now. There was one option I chose not to have it do--clean the hidden cache. Is there a reason why I would not want this cleaned out? Ccleaner said that it was occupying something like 2 gigs of space, which sounds like a lot. FWIW the overall storage is something like 12gigs used out of 26 available or something like that.