In this paper,we describe the design considerations and implementation of a smart toy system,a technology for supporting the automatic recording and analysis for detecting developmental delays recognition when children play using the smart toy. To achieve this goal,we take advantage of the current commercial sensor features (reliability,low consumption,easy integration,etc.) to develop a series of sensor-based low-cost devices. Specifically,our prototype system consists of a tower of cubes augmented with wireless sensing capabilities and a mobile computing platform that collect the information sent from the cubes allowing the later analysis by childhood development professionals in order to verify a normal behaviour or to detect a potential...