IRF
International Raumschach Federation
Raumschach for Android
The official app · Version 1.0 · raumschach.org
I. The Application
The Raumschach app is the Federation’s own game client — the same client playable in the browser at raumschach.org/raumschach — packaged as a native Android application. It contains the complete Normal Form (1926) rules, the full ladder of computer opponents from Boy to The Machine, and RGN recording, exactly as on the website. Once installed, it functions entirely offline: on an aeroplane, in a basement, on a device with no SIM card and no Wi‑Fi, the game plays identically.
Links within the app that lead beyond the game itself — to the Privacy Policy, the Charter, or any other page of this site — open in your own browser, never inside the app.
II. Privacy
Most applications ask the operating system for permissions: access to the network, to storage, to contacts, to location. The Raumschach app requests none. Its manifest declares zero permissions — not even INTERNET. This is not a promise of restraint; it is a structural incapacity. Android itself forbids the app from transmitting anything to anyone, because the app never asked to.
- No network access. The app cannot connect to the Internet at all. There is no telemetry, no analytics, no “phoning home,” no update checks.
- No accounts. Nothing to sign up for, sign in to, or be identified by.
- No advertising. Nothing is shown, tracked, or sold.
- No third parties. The app is not distributed through the Google Play Store, and installing it involves no Google account and no Google services.
- Verifiable. Every claim above can be checked by anyone with standard Android tooling: aapt2 dump badging raumschach.apk lists the requested permissions — and the list is empty.
Saved games and preferences are stored on your device only, using the app’s local storage. They never leave it. Uninstalling the app removes them.
III. Download & Installation
Because the app is distributed outside the Play Store (deliberately — see Privacy Policy), Android will describe the installation as coming from an “unknown source.” The source is not unknown; it is this Federation. The warning is Android’s standard caution for any app not obtained through Google, and proceeding is safe provided you verify the download as described in § IV.
Installation
- On your Android device, download raumschach.apk (English only).
- Open the downloaded file (from the notification, or from your Files app).
- If prompted, permit your browser or file manager to “install unknown apps.” This grants the permission to that app of yours, once; it is Android’s consent mechanism, and you may revoke it afterward in Settings.
- Confirm the installation. Note what Android reports: the app requests no permissions.
- Open Raumschach from your launcher. Play.
On newer devices in some regions, Android may additionally note that the developer is not “verified.” Verification, in Google’s sense, means the developer has registered their government identity with Google; the Federation, for reasons the reader of this site will anticipate, has not. Android’s own “advanced flow” for installing such applications remains available, and the cryptographic verification below is stronger evidence of authenticity than any registry.
IV. Verifying the Download
Two independent checks establish that the file you received is the file the Federation published.
1. The checksum. The SHA‑256 digest of the published APK is:
d555eed7243a548af5a8e54328989802221420bd50584fad88f89f09bf07e59c
On Linux or macOS: sha256sum raumschach.apk (or shasum -a 256). On Windows: certutil -hashfile raumschach.apk SHA256. The output must match the digest above exactly. This confirms the file was not corrupted or altered in transit.
2. The signature. Every version of the app, present and future, is signed by the Federation’s release key. Its certificate’s SHA‑256 fingerprint is:
c7bc19be53038e940888621a2696db1a08e8a730ce61c19efa1f86377933fb38
Anyone with the Android build tools may confirm it: apksigner verify --print-certs raumschach.apk. Android itself enforces this signature: a future update signed by any other key will be refused by the operating system. The fingerprint above is therefore the durable identity of the app, across all versions.
V. Updates
Because the app cannot access the network, it cannot and will not check for updates. New versions, when the game client itself advances, will be published on this page with a new checksum; installing a new version over the old preserves your saved games. The version you have will continue to work indefinitely — software without a network dependency does not expire.