Sachy is one of the historical engines we used to run ten years ago, written by Martin Macok from Czech Rep. I've got little hope to get it validated for RAPIDROID. However, if it passes the tests, Sachy is a "strong" candidate to fight for the last place with OliveChess.
Anyways, i'm never against weak engines. They add statistical value to any rating list by filling empty gaps of the distribution, consequently linking distant engine clusters.
Download Sachy: HERE
P.S.: Failed both fixed time per move and Fischer clock tests. Unfortunately, Sachy won't be in RAPIDROID but you can still use it to play individual games.