(adsbygoogle = window.adsbygoogle || []).push({}); (I'm fairly certain you do not need a JB for this).

You will need the Minecraft Pocket Edition from the App Store


Use iFunbox or your favorite manager and navigate to var/mobile/applications/A13DF3C5-92FF-4A2A-9554-427AE0DAFE7F (or if you can find the name, you can just pick Minecraft PE)

Then go into documents/games/com.mojang/minecraftWorlds/*your world name here*
Copy that folder to your desktop and upload it here. Post the link here and tell a little bit about it.

Download the map you want, extract it, then place those files into your iDevice and go play them.