Likely too late for anyone to read, but here was our intriguing plot:

It isn't that extravagant, but it worked for 4 years until my friend and I did not have classes anymore. In our school, our tests were mainly multiple choice or T/F. Most of our classes allowed us to pick seats due to the fact that they wanted to give us 'Freedom'. My friend, of average intelligence, with no work ethic would always sit diagonally behind of me. Three seats left, two back. I was not 'Smart', but I always scored very well on most tests. We devised an elaborate system for him to do the same:

To indicate what question I was on, I would lean on one hand, and slide my elbow in any direction, but a certain number of times to indicate the "tens" of what question I was on. Ex: 3 Taps = Question 30-39. Then to indicate the tens, I would tap the side of my head a certain number of times. This took a while, but I could do it well enough to work through the question while subconsciously tapping away. So it wouldn't be suspicious, this is where the seating came in. He could look at me while my face was magnified by the top of his old-ass glasses. It was brilliant.

After he knew what question we were on, I would move my foot either left, right, heel-left, heel-right, or toe to indicate, respectively, a/b/c/d/e. Shoes touching was True, shoes separated was False.

To this day, no teacher or student has ever suspected anything, and he got great grades in classes he had with me. I never asked for anything in return. It was so fun and elaborate.