WorldMaster
Enable flying on server, if used in survival
May produce lag, if you have to many chunk loaders
May produce lag, if world is created or regenerated
Every world has always loaded spawn chunks which may produce lag
Level-Name in server.properties has to be "world"
Installation
Copy the .jar file into your plugins directory of your server.
Start the server. If the server was already started, type "/reload" in the server console.
WARNING: If you use WorldMaster v1.0.5 or b1.0.6 with a wrong Spigot version, some things won't work as expected! (e.g.: Join/Leave Messages, Permissions)
Documentation
Documentation on GitHub