Chosen Solution

The device is very slow

This should solve the problem, you will not lose data following the steps below.

  1. Switch off your device
  2. Boot into recovery by pressing Power button + Home button + Volume up button
  3. Navigate to wipe cache partition and press power button (on some devices it will show Error but don’t worry)
  4. Device will reboot automatically Source: http://forum.xda-developers.com/showthre…