Skyblock is another classic gamemode that is also available on MCPE servers. After joining MC PE Skyblock server you can pick your island or join existing island, if you get invite.
Skyblock MCPE servers...
Skyblock MCPE servers tend to be a bit more difficult since you gotta be super careful not to fall of your Skyblock island. Aside from that you still have to build your own Skyblock island with just a few Minecraft PE resources.
Some Minecraft Pocket Edition Skyblock servers also provide a list of top islands and keep track of blocks and their values.