1- Make sure you do not give your users administrators rights. Doing so is one of the basics to help you prevent your users from accessing sensible data.
2- Open an AdminTool and click on the "Applications" tile.
Click on the "Assign Application" tab:
Select a user from the list on the left and check the "TSplus Remote Taskbar" application.On the example below the next time the demo user will open a session he will see only the TSPlus Remote Taskbar as well as other applications assigned to him, but no Remote Desktop:
Here is the result : Only a taskbar and the assigned application (in this case, a shared folder) is visible for the user "John".