Theres no real end to minecraft and by that I mean u can keep building for as long as you want but you can find a little underground room with the "End" portal and it takes you to where you fight a dragon ( u have to use a bow ) and if you kill it, it scrolls down a poem and credits with music and you also get a bunch of XP. After that you can go back to building! PLEASE VOTE MY PROFILE :D
The main objective of the PE edition is the same as the original edition. However, a few features have been added and you have to survive through the challenges to win the game. See details at http://www.minecraftwiki.net/wiki/Pocket_Edition.