Delete your account and data
Where your account lives
Your account exists only in the library on your own Mac. The author has no copy and no access to it.
Delete the account
Open Phonotheque → Settings → Account → “Delete account”, then confirm with your password. The account, its playlists and its history are removed from your Mac.
The owner can also remove any other account from Settings → Users.
Delete everything
Quit the Mac app and delete the folder ~/Library/Application Support/Phonotheque. Your music files are never touched.
On the phone, uninstall the app — downloaded tracks and saved addresses go with it.