In Minecraft pocket edition flat worlds, the worlds are not infinite
I USE A IPAD 5, BUT THAT IS NOT A DEVICE OPTION.

How to recreate:
1. Make new world on device running 1.2.14 version of Minecraft.
2. Set to “Creative” “Peaceful” “Cheats on” “Always day” “Mob spawning off” and “Weather cycle off”
3. Once in world, turn off both “Always day” and “Do daylight cycle”
4. Build a house.
5. Once done, update minecraft to version 1.2.15.
6. Fly. Around world, far away, this should happen.