Scanner for Remote Desktop (macOS version) should be uninstalled in the non-standard way because it contains daemon and plugins for other applications.
1. Open Finder and go to Applications > Utilities.
2. Launch the Terminal.app and execute the following command:
sudo /Applications/Scanner for Remote Desktop.app/Contents/MacOS/uninstall
3. In Finder, go to Applications and remove Scanner for Remote Desktop.app to trash.