Skyblock is a very popular map for Minecraft on PC. It has hundreds of thousands of downloads there and is expected to reach the same numbers on Pocket Edition soon. Far up skin change minecraft pe the sky is a floating island built. It’s only a few blocks in size with a tree and a chest on top.
From here you have to survive as long as you can on the skyblock. See how long you can make it on the island! Perhaps you manage to expand it and create a self sustainable city in the future. If done correctly you should see map in minecraft app.