You are trying to uninstall following this article but ShortPoint controls still showing up.

Details Reported by one of our users

I have removed ShortPoint from our App Catalog and from Site Contents but we still see an error message about our trial as well as ShortPoint insertion tools.

The Solution

This may happen if you missed first step - uninstalling the Add-in from Dashboard. The fix is simple - install the Add-in again, make sure to check Site Collection check box.

Then uninstall uninstall following this article.

If it didn't help - repeat the procedure with Site Collection checkbox left unchecked.