This app using Tensorflow with pose estimation.

Semaphore ("apparatus for signalling," from Greek sema "sign, signal" and phoros "bearer")[1] is the use of an apparatus to create a visual signal transmitted over distance.[2][3] A semaphore can be performed with devices including: fire, lights, flags, sunlight and moving arms.[2][3][4] Semaphores can be used for telegraphy when arranged in visually connected networks, or for traffic signalling such as in railway systems, or traffic lights in cities.[5]