Matefinder is a fork of Stockfish engine specially tuned for finding checkmating variations. I've read it's maintained by Joseph Ellis but i don't have a deep knowledge about its abilities.
I'm not interested in rating its chess strength and introduce it in Rapidroid. Meanwhile, those who wish to use it for chess puzzles may enjoy two compiles made by Jim Ablett.
On December 23th Jim has released reworked versions based on commit 1e8836d expected to run without crash on Android devices. Below new links replace the old ones which crashed on load and will direct you to the corrected builds:
Download arm5 binary: HERE
Download arm7 binary: HERE