Play full games against a graded bot, keep a personal, reviewable archive of every game and replay it roll by roll, drill hit-spotting in a calm rated ladder, and reason through real board decisions — the pip race, the doubling cube, bearing off, the back game — with a coach that explains in words. It runs on this device; only the optional, pseudonymous account, if you choose it, syncs your game archive and rating across your own devices.