In this paper, we propose a novel rapid prototyping platform called SenStick, which is composed of both hardware and software. The main purpose of our platform is to sensorize our personal belongings easily and smart for recognizing our living activities. The most impressive point is its size. The size is 75mm(W) x 10mm(H) x 5mm(D) and its weight is around 3 (g) including a battery. On this tiny board, 8 sensors (acceleration, gyro, magnetic, light, UV, temperature, humidity, and pressure), flash memory, BLE, and battery are embedded in high density. The battery life in stand-alone mode is more than 12 hours. Second interesting point is the support software for iOS and Android OS. It can monitor the sensing data as well as can record the ground truth video simultaneously and synchronously. Furthermore, 3D CAD data of various case designs will be open for users in SenStick community site. As a result, SenStick enables everyone to sense every activities easily and smart.