This paper presents a system that reports the harvested energy from a wearable piezoelectric generator to a mobile application in real time. The system is adapted to be worn as a bracelet, harvesting energy from wrist movements during physical activities. A mobile app connects automatically to the harvesting monitor, tracks and stores the harvested voltage and power values, and also can compute the total harvested energy during a customizable time window. Test results showed that some arm movements displayed enough harvested energy to obtain a sample from a heart rate tracker and transmit it to a mobile device. Moreover, the harvested energy from jogging during 30 minutes can supply the tracker up to 37 sampling cycles. The developed system allows real-time harvesting monitoring, which can be used to determine the suitability of kinetic energy harvesters with the advantages of mobile computing.