Kwa Uzoefu wangu hizi ndo zinasababisha
① Ant virus ulizoweka mara avast,clean master, jaribu ku-unstall moja wapo
② Memory card ni ndogo halafu imejaa.. Tafuta memory kubwa
③ Background application. Jaribu kutumia back button kuliko menu button ku close application
④ kuna application zinakula sana phone storage mfano Facebook,Chrome Browser,Opera
Best Solution ni FACTORY RESET.. ila hakikisha unefanya backup ya Data zako kwenye memory card yako.