Where is flight following available?
In the US, you can get flight following anywhere there is radar services from ATC. It is not dependent on a control tower. However, it is dependent on ATC workload. Most controllers in our area would prefer to talk to every blip on their screen. Especially near or under their Bravo shelves.
You can pick up flight following by contacting the appropriate controlling authority/agency in controlled airspace. If you are at an airfield with a control tower, find out from them if they have radar services. Some Class D airports do have it. They will give you an abbreviated CRAFT clearance (more than likely when you contact Ground) so that Approach Control can identify you after takeoff and climb out.
If the airfield does not have a tower with radar services, you will have to climb to an altitude to be able to be seen on either Approach or Center’s radar. Cold call them on your initial call with just your tail number and the words “with request”. When/if they respond, request flight following to your destination at your desired altitude. They will let you know if their workload permits it. If they do not respond, climb higher and/or fly further into their controlling airspace (unless you have not received clearance when applicable). Or, you can try another nearby controlling agency.
Your sectional chart will tell you the information for Approach and Center. If you have difficulty locating it, look at the approach, arrival, or departure charts of any airport with instrument procedures, regardless of if they have a tower. Another alternative for getting the information is the US Cart Supplement. The controlling authority/agency information will be listed if they provide radar services to the airfield.
You can also request flight following while airborne enroute or within the terminal arrival area. Some busy airports actually require it. The information for Approach may be listed on the ATIS in this case.