A super simple world generator. Nothing more, No BS.

How to create a flat world
Download the plugin, put it on your server and reload/restart.

Using multiverse, create a normal world in the same way as you normally, would, but add -g FlatWorldGenerator on the end
Example:

Code (Text):

/mv create myendworld end -g FlatWorldGenerator

To change the world height
Simply edit /plugins/FlatWorldGenerator/config.yml and change the height: to the maximum Y coordinate.
Then, reload the plugin.

Here's a Video
Here's a video of an end world being created.