My complaint about this and other mods about flying vehicles is controls, now I do understand that modders can't do anything about it, but Mojang must help them out with this.
Credits: JPlaysPE
How to find an UFO in MCPE
- UFO replaces Skeleton, they can spawn almost anywhere in the Overworld.
 - UFOs won't fly around, in fact they will move on the ground, until you use Light Blue Egg on it (Egg).
 - To enter the flying saucer, make a long press on the UFO and press "Ride".
 - After throwing Light Blue Egg in it, you will start gaining altitude very quickly, up to the vertical end of the world.
 - To control saucer in the air, use a Key (Carrot on a stick).
 



How to install addons:
- Download addon into your device
 - Find and open .mcpack or .mcworld files that you download earlier
 - Click on it to import into Minecraft Pocket Edition
 - Open the game
 - Create new or edit an existing world
 - Scroll down to Add-ons section and select the ones you want to apply