[This](https://github.com/Guardsquare/proguard) compiler, available under the [GPL v2](https://github.com/Guardsquare/proguard/blob/master/LICENSE), claims to make Java apps up to 90% smaller and 20% faster. I suggest you try it out.
This compiler, available under the GPL v2, claims to make Java apps up to 90% smaller and 20% faster. I suggest you try it out.