Well, it seems you are trying to build something, rather than providing a solution for us to use.
I have taken a look, and I found several hardcoded paths and basically everything else was Linux. Now I don't have a problem with Linux, as my webservice runs on Linux (including 7zip through wine), so I'm not even too biased. But very few are using Linux on our dev machine.
What you have written may be useful to you, but in the current version, you should not expect many people to jump in and use or improve it. People are lazy, truly lazy, what's why I'm not even making anybody upload a classfile, it's just too much hassle. For most it is good enough, and others simply already rolled their own.
Don't get me wrong, I'd love to see you do a better job than my 4K shrinker!
You're absolutely right. In time i hope that it can become a tool that people actually can use. When the project is decent enough i'll publish the source and binaries. But right now it's doesn't really work properly.
All commands are stored in settings.properties which is generated in CWD on the first start of the application. This is kind of hard to understand since there is no readme or anything, just a tiny tiny log row

Anyway, in that file, the path to each binary is defined along with the necessary parameters. The toolchain is fixed for now but in time that might be configurable as well.