I recently came across the boofcv project and it is really amazing. I like it because it is very easy to use. I adjusted this example: http://boofcv.org/index.php?title=Example_Associate_Interest_Points to work on android. But this feature uses Surf and as far as I know the version of surf included in BoofCV is not free for commercial purposes. BRISK, ORB, etc. may work as well but I don't know how to implement them.
Two questions: Is SURF free in combination with boofcv? and If not: How can I modify the example code to work with a free-for-commercial-use Feature Matcher/Descriptor/Extractor?
(BoofCV seems to be the best choice for beginners that are completely new to Computer Vision and Android development, doesn't it?)