CruxCoach

CruxCoach is an open-source Android app for seven LED training boards: the Kilter Board, the MoonBoard, and the Tension, Grasshopper, Decoy, So iLL and Touchstone boards. Browse over 650,000 climbs offline, light up the holds on the physical board over Bluetooth, and log every send, attempt and rating, all without creating an account.

Built in 2026 as an independent alternative after the Aurora-operated Kilter app was withdrawn, CruxCoach prioritises data ownership. No central account server, no Google Play Services dependency, no user tracking, no third-party SDKs. Your identity is a Nostr keypair generated locally; your logbook lives in a SQLCipher-encrypted database whose key never leaves your device.

Filter climbs by grade, angle, quality, move count or setter. Set custom hold colours. Search by tapping holds on the board image. Optionally import your existing Kilter logbook, then export anytime as JSON or as an encrypted backup only you can restore. Set your own climbs and share them over Nostr, with no central server holding them.

Distributed via Zapstore (Nostr-native Android store), as a signed APK from Codeberg releases, and via Obtainium, which tracks those releases directly. Runs on de-Googled Android (GrapheneOS, /e/OS, LineageOS) just as well as on stock Android 8.0 or later with Bluetooth LE. UI in German and English. A companion board locations map (https://cruxcoach.org/boards/) plots more than 2,800 Kilter, MoonBoard and Tension venues worldwide.