If you open up Amazon’s App Store on Android today you’ll see that Lock ‘n’ Roll Pro is the current free offering. The strategic dice game usually runs $0.99 for the add-free version. Gameplay consists of moving dice into a 4 X 4 grid in an attempt to create straights, number combos, and various collections of the multi-colored dice. Point earning lines and cubes will disappear when the roll button is clicked, and four new dice slide into the hopper. It’s a simple concept with a lot of variations and is good for a little brain exercise while killing time.