Welcome to the Android Domination!!!!! Apple is the biggest Enemy so great lol.
Anyway, useful:
Candle - it's pointless but awesome
Flashlight - when you need to see in dark
QR Code Scanner - .... self explanotary.
Daily Smash Bros.Screen - pic of the days in your hand + stuff.
Ringtone/Wallpaper apps.
Viber - if you have free internet then.......you can call and text for free from there.
GEOMETRY DASH LITE! Most Indie- like game I found.