When Minecraft Pocket Edition first launched, it wasn’t anything like the desktop (and now Xbox 360) versions; it was a neutered stub of a game. But with each update, the PE version gets more and more awesome as it adds the cool features of its big brothers. This update brings wearable armor, craftable signs, new renewable resources in the form of baby livestock and makes gravel and sand follow the rules of gravity.
Unfortunately, there might also be a bug that destroys your entire world.
Other improvements include fancy clouds, the ability to dye sheep different colors (as a source of colored wool), improved D-pad controls and a whole bunch of stuff to do with netherrack.