Recently there has been a growing interest in consumerization of wrist-worn devices especially smart watches and wrist bands. Many large corporations such as Samsung and Apple already have a commodity smart watch and many other companies such as FitBit, Nike, Jawbone have wristbands geared towards fitness tracking. Smart-watches and bands are equipped with many sensors, (for example, latest Samsung Gear devices have heart rate, accelerometer, gyroscope, infrared sensors etc.) a processor, communication radios (for example, Bluetooth or Wi-Fi) and a small size display. It is, therefore, possible to capture information about the device user, perform computation and communication using these devices to infer various activities/contexts of the user. Further, they also represent a perfect platform to conduct research on human activity, behavior, and related areas, given the capabilities described above. Moreover, compared to smartphones, wrist-worn smart devices provide richer information about certain user activities (e.g., eating, typing, and sleeping). In most cases, a smart-watch is also connected to a powerful smartphone, which could help in drawing many interesting inferences by combining data from both these devices.