How do I build this project?

[djsigmann]

Just to clarify, I'm not very familiar with neither java or any of its build tools (gradle, maven, etc.), nor android development in general, and even though I've tried to build this project, I just get build errors.

I see there's a file called build.xml in the project root, but I'm still not sure what tool to use it with.

So how would I go about building this application and compiling it into an apk?