A free, open-source MoonBoard app for Android

CruxCoach browses the full MoonBoard problem catalogue and lights up the holds on your physical board over Bluetooth — with no account, no Google services, and the same app that also drives your Kilter and Tension boards.

Install CruxCoach

Free, no strings attached. The recommended route is Zapstore, a privacy-respecting Android store that verifies developer signatures and auto-updates; the signed APK from Codeberg works just as well, with the in-app updater handling future releases. One APK button uses a first-party selector to choose the currently available verified Codeberg copy or its identical, content-addressed Zapstore mirror.

Download CruxCoach

Free. No account. Verifiable signed builds. Android 8.0+.

What CruxCoach does with the MoonBoard

Browse the problem catalogue offline. The full official catalogue contains about 272,750 problems across five configurations. Sync the catalogues you need, then filter them offline by grade, angle, quality, move count and setter.
Light up the holds over Bluetooth LE. Open a problem and send it directly to the board. Start, hand and top holds use the fixed role colours supported by the MoonBoard LED kit.
Set and share your own problems over Nostr, with no central server holding them.
One app for every board. The same install also drives Kilter, Tension, Grasshopper, Decoy, So iLL and Touchstone.
Encrypted local logbook. Your sends, attempts and sessions stay on your device in an SQLCipher database.

No Google account or services required

The current official MoonBoard app offers sign-in with Apple or Google. CruxCoach takes a different route: it creates no conventional account and has no Google Mobile Services dependency.

That makes it suitable for de-Googled Android setups such as GrapheneOS, CalyxOS, /e/OS or LineageOS without GApps. It installs from Zapstore or a signed APK, and updates without the Play Store or Play Integrity. No account, no Google Mobile Services, and no user tracking. Website analytics are limited to the anonymous aggregate page/click counters described in the privacy notice.

Supported MoonBoard configurations

MoonBoard 2016 (25° and 40°)
Masters 2017 (25° and 40°)
Masters 2019 (25° and 40°)
Mini 2020 (40°)
MoonBoard 2024 (25° and 40°)

What CruxCoach is — and isn't

CruxCoach is a community project, not affiliated with Moon Climbing; "MoonBoard" is used only to describe hardware compatibility. It is Android-only (8.0 or later, with Bluetooth LE) and open source under the GPL-3.0 — anyone can audit, fork and build it from Codeberg. If you need an iOS app, this isn't it.