Mod The The Nether with which you can create a portal to HELL and visit the underground world in the game Minecraft PE 0.10.4, which is fraught with many dangers and looks horrific. The process of creating a portal to the underworld of chaos, very simply, for this, you don't need special items or rare materials - all you need to put obsidian blocks, as shown in the picture below.
So the portal you have installed, just tap on the bottom, the Central block of flint and a portal will open, you just have to enter it and then in the blink of an eye you'll go to HELL.
In the archive you'll find three different versions of the mod The Nether, in fact they are the same, but in each there are not big changes and what mod for Pocket Edition to choose, only you can decide. To get back, build the same port into Hell in Minecraft PE then you die, but your stuff will not disappear and you will return to the ordinary world.