@Rancs ndk-build internally uses make to build so i doubt it would be much faster than the OF toolchain. For me compiling the empty example, including ofxAndroid, in debug also takes 35s. even if ndk-build used a faster build system like ninja or qbs it wouldn't make a big difference since most of the time (by orders of magnitude) is spent in compiling the actual code.
@racarate, i don't remember right now if 0.8.4 compiled all the platforms in debug but if it did you can set it to only compile arm so it's faster while you develop by adding:
ABIS_TO_COMPILE_DEBUG = armv7at the end of the config.make file for your project. it's super anoying that adt always tries to compile every project at the beginning but in the end if only recompiles whatever has changed and you can always stop it or just let it recompile in the background while you keep working. it's also adviceable to have as few projects as possible open in the workspace so the times it takes to recompile are shorter