Follow these steps to install SynCal on your Android device safely.
Download the official SynCal APK using the button above.
If Android shows a Play Protect warning, it happens because the app is not yet published on the Play Store. Tap “Install anyway” only if you trust the source (this official page). SynCal is safe and signed by the developer (Calbrs).
Go to Settings → Security → Install unknown apps → Enable for your browser or file manager.
Open the downloaded APK and tap Install. Wait for the process to finish.
Open SynCal and start using it for class communication and announcements.