To get past this, just open your Applications folder (in Finder). If "TntConnect" exists, delete it. Then rename "TntConnect 2" to "TntConnect".
The last time you updated TntConnect for Mac, you were asked to copy the new TntConnect into your Applications folder. Since there was an existing TntConnect in your Applications folder, your Mac gave you three options: "Keep Both", "Replace", and "Stop". You probably chose "Keep Both" so it added in your new TntConnect as "TntConnect 2".
To avoid this, next time you update TntConnect, be sure to choose "Replace" when prompted.