Fully functional coordinates in the Minecraft Pocket Edition 1.2 are implemented through the mod called Coords Unlocker (Coordinates). It has been tested on devices running Windows 10 and Android, and no issues have been reported so far. While there are numerous mods available for coordinates, users have indicated that problems arise with beta versions of MCPE. Therefore, if you need coordinates for version 1.2, the provided mod is the best choice!
How do unlocked coordinates work?
Coordinates (x, y, z) will be displayed in the bottom right corner of the screen. They cannot be disabled by any means other than turning off the resource pack.