Download

1. Check the signing certificate

Every Field Watch release is signed with the same key. Its certificate fingerprint (SHA-256) is:

09:64:18:6E:94:67:B3:13:8C:3E:EA:9B:E0:6E:0B:23:07:99:6F:62:07:C9:75:EE:F7:27:82:FE:3D:11:CF:CC

Without colons, as apksigner prints it:

0964186e9467b3138c3eea9be06e0b2307996f6207c975eef72782fe3d11cfcc

If the APK you downloaded shows any other fingerprint, don’t install it.

With apksigner

On a computer, apksigner comes with the Android SDK build tools. On the phone, in Termux: pkg install apksigner. Then run:

apksigner verify --print-certs field-watch.apk

Look for this line and compare every character:

Signer #1 certificate SHA-256 digest: 0964186e9467b3138c3eea9be06e0b2307996f6207c975eef72782fe3d11cfcc

Why not keytool

keytool -printcert -jarfile can’t read this APK. It only understands the older JAR signature, and Field Watch is signed with APK Signature Scheme v2, so keytool says “Not a signed jar file”. That message doesn’t mean the APK is unsigned. Use apksigner.

The file itself

Each build also has its own SHA-256 file hash, published next to the APK as field-watch.apk.sha256. It changes with every build; the certificate above doesn’t. With both files in the same folder:

sha256sum -c field-watch.apk.sha256

2. Install

1. Open the downloaded APK from your notifications or the Files app.
2. Android asks whether to allow installs from that app (your browser or Files). Allow it for this install.
3. Tap Install. Android may show an extra warning for apps that don’t come from an app store.
4. Optional: turn the permission back off afterwards in Settings, under Apps, Special app access, Install unknown apps.
5. Open Field Watch and unlock with your fingerprint, face or screen-lock PIN, pattern or password. There is no separate app password.

Later releases signed with the same key install over this one and keep your data. Android refuses an update signed with a different key. Never uninstall to update: uninstalling deletes the vault.

3. Moving over from Field Watch Preview

The Preview is a separate app with its own vault. Installing the release doesn’t change it, and the release starts empty. To bring your records across:

1. Back up in the Preview. Open Field Watch Preview. On its lock screen, tap Back up my data, choose Portable full backup (no password), and save the file somewhere private that you control.
2. Install the release as above. The Preview stays installed for now.
3. Restore in the release. Open Field Watch. On its lock screen, tap Restore a backup and pick the file you just saved.
4. Check it. Open your notes and resources and make sure everything is there.
5. Uninstall the Preview only after that check. Uninstalling deletes the Preview’s vault.

The backup file is not encrypted and has no password. Anyone who has it can read your records. Once the restore checks out, delete it or move it somewhere you trust.