I own iPad 1 & iPad 3 which I used to play together while iPad 1 hosts the game.
Used iPad 1 to run a creative world and couldn't joined the game with iPad 3
It worked fine till I updated both iPads to last 0.6 version
Steps to Reproduce:
1. Run creative world in iPad 1
2. Join game with iPad 3 device
3. iPad 3 see blank world and get disconnect msg after a few secongs
What actually happened was...:
iPad 3 saw the world but it was empty
Since that happens, even a local game mode is not working well, changes are not saved and are cleared upon exit and start game again.
It's related to MCPE-1216
The upcoming 0.6.1 release will fix this issue