I've been trying to import one of my survival worlds onto my pocketmine server. There's just better land generation and the big trees... Anyways, I would put the world file from my phone to the worlds folder in the pocketmine directory. I tried finding a plugin to load the world, but "Worlds," the plugin I attempted this with, won't give any commands in /help. To bypass the need for a plugin, I deleted the default world and imported the new world. I renamed the world folder to "world," I edited the world name file to "world." The command prompt says it couldn't find a world and starts generating a new one. I've also tried swapping out the level.dat, not sure how much that'd even do, but the server won't even startup then.
Pocketmine doesn't really support the MCPE world format, AFAIK. You can convert it however, or generate a Minecraft PC world and import it in (PocketMine supports the world format that PC uses).
I'm clearly still doing something wrong. I import the pc world into the pocketmine worlds folder and delete the original. I rename the new folder to "world." I start up the server, join, and it's back to the old world\ nevermind. Typed /spawn and its the pc world
The only thing you have to do now is to edit the level name level.dat with an nbt editor otherwise some plugins could glitch really hard