The Android build for this app has been signed with a developer certificate which can generate warnings on some phones.
Be sure to turn on "Unknown Sources" in the list of places you allow software from in "Settings" -> "Security".
You may also see a warning from "Google Play Protect", these can be dismissed to use the app downloaded.
This build includes a macOS download that has not been notarised which can trigger warnings after download. The fix is to remove the quarantine flag, which you can do by opening the Terminal and executing the following command:
sudo xattr -r -d com.apple.quarantine "Nomad.app"More information is available at docs.fyne.io.