Any of the above--especially the basic air nozzle, tire gauge, impact wrench, etc.
Top Auto Mechanic Tools: The Family Handyman
Air Tool Station - A bucket is all you need to store air tools and hoses on a wall right by the air compressor. Screw a plywood…
Air Tools EZ Organizer
In-Line Oiler Doesn't Forget to Oil - You add oil to it. It adds oil to your air tool. Not exactly rocket science. Find one in the air tool section at any home center.