From Zepp Labs (zepp.com) comes the $150 Zepp multi-sport sensor. Attach the sensor to the handle of any tennis racket, baseball bat or golf club. Load the sport specific app to a smartphone or tablet and then capture and analyze the action in 3D. The Zepp Tennis app shows important serve metrics such as racket speed, ball speed potential, spin, backswing time, sweet spot contact and impact time, which gives players and coaches a scientific way to evaluate performance on the court. Zepp Golf and Zepp Baseball apps provide similar insights for the respective sports.