Play store won't let me download any apps My internal storage is about 50MB and my SD Card is about 300 MB. When I want to download an app that only need 20 something MB, it says insufficient storage. Even though I delet most of my apps and make my internal storage to about 100MB, it still says insufficient storage when I want to download an app that need 20MB. Please help me to solve this problem as soon as possible.
Use high storage SD card if possible (at least 2GB) 
Move your installed applications into SD card from the settings.
Reset application preferences from the 'settings > apps'.
Go to 'Settings > Storage' and choose SD card as a preferred install location.
Reboot the phone.
Download any application after above steps.