Recs.
Updated
Minecraft - Pocket Edition is an indie sandbox video game based around building structures in a voxel based world. Contained within are survival and a free play build modes. The game can be played offline and with others over Wi-Fi.
SpecsUpdate
Pros
Pro Completely new experience with each generated world keeps the game fresh
Each new world a player starts is randomly generated, making for a different experience every time a new world is started. There are 38 biomes - snowy, cold, medium/lush, dry/warm, and neutral biomes, each with numerous sub-biomes (such as mountainous, rivers, forested, swamp, beach and more). These biomes each have their own set of blocks and configurations, and each frozen river biome will be different from the next frozen fiver biome you see.
Pro Active development means plenty of new features and fixed bugs
There are updates to the game all the time, new features do get added at a good pace, which means that not only do bugs get fixed but that the game will constantly be growing as the platform grows with it, which allows more demanding features to be added with time.