But for us poor people who still rely on a baked beans can and a piece of string
I needed an incidence checker in a hurry the other day to check for any twist in a wing. As the wing was flat bottomed I knocked up something quick and crude, very crude, but it did the job.
A stick, a piece of paper, a piece of wire, (actually an old bike spoke), and a rubber band. Stick the paper to the stick, poke a hole in the paper for the wire pendulum, (swing-ometer). Sorry no plans available.
The 'instrument' attached under the wing and was held in place by the rubber band over the wing.
Then moved along the wing from the center section, 1/4 span, 1/2, 3/4, and tip, and the 'swing-ometer' checked for any change. (Eyeballing just couldn't be sure).
So quick and crude, but works. (Now where do I remember hearing that before ??, but then they also called me, 'slow and........'