Drywall screw guns are the standard tool for fastening drywall panels to wood or metal framing. Common corded models have a trigger lock-on button for continuous operation, a magnetic insert-bit holder that prevents screws from falling off the bit, and a nosepiece that fits over the bit holder to serve as an adjustable depth stop.
They also have a clutch consisting of two mating ratchet plates held apart by a spring. At rest, the clutch isolates the bit holder from the motor, allowing you to feed screws onto the bit with the trigger locked on. Once you load a screw, you push the tip against the drywall to engage the clutch, which drives the screw until the nosepiece hits the drywall and the clutch slips. Properly set, the unblemished countersunk screws leave a perfect dimple without tearing the drywall face paper or damaging the bit. The noses easily pop off so you can extract errant screws in reverse, swap bits, or work without the depth stop.
These tools cost about $80 to $180, which is reasonable for drywallers but hard to justify for remodelers who only occasionally hang drywall. One alternative is to chuck a heavy-duty Bosch Dimpler drywall driver into your existing corded or cordless drill. It will give you most of the benefits of a dedicated screw gun at a fraction of the cost.
The Dimpler has been around for years but was recently redesigned to provide better access into inside corners. Like drywall screw guns, it has a magnetic insert-bit holder, a depth stop, and a clutch. Its depth stop is fixed, though, so the tool consistently countersinks screwheads a millimeter deep and leaves a slight dimple. To change bits or to remove a screw, you simply push and twist the head, which exposes more of the bit and defeats the depth stop. Another push and twist resets the head for driving. You can't lock on your drill trigger and load screws while the motor runs, as you can with a screw gun, but that is a minor inconvenience.
The Dimpler is useful even for drywall contractors. I install panels using a drywall screw gun and then circle back later with a cordless drill and Dimpler to add screws where necessary or to set any high ones.
If you buy this tool online, make sure that you aren't buying the old version with the same D60498 part number (that version doesn't have a blue nose). The new Dimpler costs about $12.