Actually I'm not able to help the project with money since I live in Iran so I decided to do a little contribution with code (. ❛ ᴗ ❛.)
Here's the project I was working on for a few days.This is a Colyseus client for Java / Android that is implemented based on colyseus-unity3d and colyseus.js clients.
Github : Colyseus-Java
FossilDelta and StateContainer are written completely in Java
For websocket connection I used Java-WebSocket
MessagePack decoding is done by the MessagePack for Java
And I also made a simple agar.io-clone game using libgdx just to show how to work with it.