To save battery:

  • Don't use 3G network

  • Don't change CPU freq

  • Don't use live wallpapers

  • Use conservative governor if you use your phone for calls only

To play recorded videos:

  • Use an external player supports Mp4 encoding like MX player

Reboot phone:

  • After using Wi-Fi tethering (has reboot issue)

Use HWA Settings app:

  • To disable/enable hardware acceleration for gmail, facebook and other apps (fixes white screen issue)