In order to get better at tennis, you need to work on your forehand, backhand and other shots all the time. The PongBot Pace S can help with that. It is an AI powered tennis robot with a position sensor that can adapt to your level of play. It comes with 300+ drills and has room for 15 balls. You get a visual interface on your mobile phone for custom drills.
You can control this robot with your phone or remote. This robot launches ball at speeds up to 80mph and 60 rps spin. It can lob the balls up to 8.1m. It has serve and toss modes. It is battery powered and lasts over 8 hours. You can find this project on Kickstarter.