Open it
If macOS calls it damaged or corrupt, it is not — the app just has no
paid Apple signature yet. Paste this in Terminal once, then open
the app normally:
xattr -dr com.apple.quarantine /Applications/PhonoFilm.app
It removes the “downloaded from the internet” flag macOS
attaches. Nothing else changes. If macOS instead says it was merely
blocked, System Settings → Privacy & Security →
Open Anyway works too.