Tiny Offset Screwdriver
Here's a tool I use quite a bit. It's great for getting at those screws that you can't reach with a regular screwdriver. Most common offset screwdrivers are way too large.
I have a long one for getting to the screws that hold servos in, a short one for the servo arm screw and a very short one for tight small servos. Saves taking the servo out, when all I need to do is move the arm a notch or two. Even with servo frames, it lets the servo stay in position when moving the arm.
Just take one of those many Allen wrenches you have laying around and grind the tip.
You need to taper the sides so it fits into Phillips head screws.
side view grind
front view taper
I have both 90 deg and 30 deg. Sometimes I can only move the driver a tiny bit, but with the two angles I can pretty much get any screw out.
If you have an idea for something, but don't have the tools to make it, and it's something I can use in Tom's Tips, I'll consider making it for you and credit you with the idea. If published, it will be considered in the public domain. If you want to patent or manufacture, I charge for that service. firstname.lastname@example.org