At this point, PocketMine is falling extremely far behind with how fast MCPE is being updated. It can be caught up if everyone knows what to do and how to do it, but that isn't the case. It takes a lot of testing and who wants to make plugins for outdated versions of a software? I for one, am waiting for PocketMine to catch up to MCPE to publish more plugins. Until then, I am just gonna work on plugins for Third Party Builds.