A new gadget soon could put an end to squabbles on the tennis court. A French inventor has created £149 ($200) device that can detect whether balls are out - and he expects to sell it this summer. The device sits on the net and maps the ball's flight - using artificial intelligence (AI) to measure flight, pace and spin. The GoPro-size device, called In/Out fastens to the net and can be assembled in less than a minute. Device attaches to net and can be assembled in one minute.

Players suffer complete meltdowns as they hurl insults. Postmatch beers can undo some of the damage, but the shame and resentment linger for days. More civilized times may lie ahead. French inventor Grégoire Gentil has designed a $200 GoPro-size device that can be fastened to any net post and detect whether balls are in or out with surprising accuracy. It's called, reasonably enough, the In/Out.