Me (with Mujtaba) developed an armband proof-of-concept to control home electronics just by pointing at electronics (like a speaker, tv, lights etc) and doing a gesture to control them. The hardware consisted of IMU sensor, smart switchboard. Here's an early video.
Me (with Mujtaba) developed a very cheap armband to detect MMG signals, which we then sent to a neural network and captured/recognized few gestures. The hardware consisted of pre-amplified microphones.
A course project. We used logic gates to design classic pong. The quick hack also allowed us to add bot player.