I was just wondering how Jim Ablett compiled SamChess (posted a few days ago here) and could possibly skipped Slowchess because they share the same homepage. Slowchess is written by Jonathan Kreuzer from USA, although ironically named "slow", is known to be much stronger than Samchess. Hopefully, the wait didn't last too long and yesterday night, i've got the answer to my question, packed in a new compile by Jim. Nice!
Slowchess has 2639 ELO on CCRL scale. Interpolated to Android, it would roughly be 2450. Note that it needs to be installed as a UCI engine acording to JA.
Download Slowchess with some optional bitbase endgame files: HERE