All you have to do to install is navigate to:
iDevice:
Applications -> com.mojang.minecraftpe -> Documents -> games -> com.mojang -> minecraftWorlds
Android:
sdcard\games\com.mojang\minecraftworlds
And paste the UNZIPPED folder into there.
I am open to suggestions, if you would like a custom flatmap, just reply with your idea!
EDIT: Added bedrock and sand flatmaps as per peapodamus's request. Bedrock is just one layer of bedrock at the bottom of the map, to allow for maximum building space.
iDevice:
Applications -> com.mojang.minecraftpe -> Documents -> games -> com.mojang -> minecraftWorlds
Android:
sdcard\games\com.mojang\minecraftworlds
And paste the UNZIPPED folder into there.
I am open to suggestions, if you would like a custom flatmap, just reply with your idea!
EDIT: Added bedrock and sand flatmaps as per peapodamus's request. Bedrock is just one layer of bedrock at the bottom of the map, to allow for maximum building space.