If you are tired of standard achievement system in the game Minecraft PE 0.12.1 and 0.11.1 or you do not have enough existing units then mod Globalization
you will love it. It will completely change the achievements in the game and will add new units that will be useful in the process of building complex and not very mechanisms. Also the mod built generator houses, with which you will have the chance to quickly generate a finished house, variations of the appearance of homes over a million, so everyone will find something for themselves. Just keep in mind that the house may be generated with traps that are inside it.
Also in this mod for Pocket Edition, there are extremely useful opening chests which you will have 30% chance to find some very useful things that will be useful during the game.