3. Captain America: War Criminal
Captain America only appears three times in Spider-Man: Homecoming; the first two are in videos played in Peter Parker's high school and the third comes in a humorous after-credits scene aimed solely at the audience. However, in one of the reboot's funniest moments, Peter's gym teacher refers to Cap as a "war criminal," something which gives us a very good idea of how Steve Rogers is now perceived in the Marvel Cinematic Universe.
The Sokovia Accords are also referenced during a class Peter and Ned are in, though the fact that the wall-crawler hasn't signed them is never mentioned (perhaps he has, but it's never made clear either way). Beyond that, we don't really get any sort of teases for Avengers: Infinity War, but it will now be very interesting seeing how Spidey is incorporated into that movie and how he interacts with the "war criminal" Captain America!