SURF and SIFT are still in the nonfree package, but this package is excluded from OpenCV4Android distribution. The problem is that these algorithms are patented, so you should prefer Orb or FREAK. For those who really need to have SURF we will create an instruction on how to build the nonfree module from OpenCV sources. But this way will be incompatible with Android OpenCV Manager and you can't distribute you application on Google Play Market (technically you can, but you'll meet some difficulties).