This wearable device is a next-generation performance aid driven by advanced precision tracking, for runners who want to improve their sport. A system that can operate with accuracy and provide to the runner useful, real-time, evidence-based feedback.A complex and challenging distributed data processing & sharing scheme was devised using Bluetooth Low Energy (BLE) as the prime communication method. Moreover, novel algorithms were cleverly combined with multiple sensor technologies to enable real-time and unique analysis of the human body. Besides, Fen specified an embedded system API to support third-party App developers in creating the desired user experience.