AndEngine is a 2D OpenGL Engine. Actually a game engine. But it has also some small AR extension. I've stumbled upon this project a little while ago but then somehow forgot about it and now rediscovered it. So far it looks promising (even though I already found some kind of "lazy bug" which prevents the AR example to run 😕 ). Especially the the animation stuff and sensor helpers look great.
Hopefully this can boost my project a little.Will see.