The #1 mental performance app for tennis Based on our user data, 98% of users who utilized Apeak consistently for 5 to 15 minutes a day, at least 4 days a week, demonstrated improvement. Apeak's mental-training is led by Jim Loehr, the world renowned performance psychologist. Dr. Loehr has helped seventeen athletes to become world number ones, twelve of which are tennis players, including Novak Djokovic, Jim Courier, Monica Seles, Arantxa Sánchez Vicario, and more. He has served thousands of performers, including athletes, SWAT teams, military, and Fortune 100 CEOs.