I really like maxwxyz's Screw Claw, but I'm not fond of printing the thin screw holder fingers in the vertical orientation. I also wanted to accommodate a larger variety of screwdriver sizes. This redesign has all the flexing elements (friction fingers for grabbing the screwdriver shaft, and flexing fingers for holding the screw) printing in a horizontal orientation for maximum strength of these thin elements. It works with screwdriver shafts 4.5 - 7.5mm in diameter, as well as standard ¼" hex shank driver bits. It will handle screw heads (any style) up to 13mm in diameter.
I recommend using PLA as it is stiffer and prints a little more cleanly than PETG. It prints without supports. After printing, the two flexing fingers that grip the screwdriver shaft need to be broken away from the upper and lower surfaces. Just grab the end of the finger with some needle nose pliers and give it a little twist to free each one.
NOTE: I've seen a number of people printing this standing up. It will be much stronger if printed on its side in the orientation provided.
To use, slide the body over your screwdriver and leave room for your screwhead. Slip the screw between the fingers and then slide the body down along the screwdriver shaft until the bit engages the screwhead. Commence screwing. When the fingers hit the surface of your part, they automatically separate as the screw drives flush.