Just found yet another AR library for Android called ARmsk. The description sounds promising. But the demo video is kind of shocking. They have like half a frame per second. The code looks like they used a lot of examples, like the OpenGL Cube renderer from the Android API demos and some stuff from the OpenCV-Android examples.
Last updates were in January this year, so quite up-to-date actually.
Oh, btw, guys why can't I find you when I search for "AR Android". I mean seriously, take care of your website keywords 😉