Beyond that, the worlds have a lot more in them than before. The update adds caves, tons of new flowers, new biomes (including mesas, jungles, swamps and extreme hills), as well as abandoned mineshafts, villages, and other stuff to explore, like lakes, and monster rooms. There are also new beings to inhabit those worlds, including wolves, endermen, and Mooshrooms. And, of course, there are new blocks including Monster Eggs and huge mushroom blocks.
There has also been a change made to the controls, adding a new "interaction" button, which should keep you from accidentally punching something that you don't want to. Last on the change log is the requisite bug fixes, but we're amused to say that Mojang has been nice enough to note that there were likely new bugs introduced along with the new features.
Minecraft Pocket Edition has been updated for both Android and iOS. If you haven't purchased the game, it will cost you $6.99 on either platform.