Many of the Cortex M0s are very good at conserving power, and have a number of low-power and sleep modes, which make running at these levels quite easy. On the

Many of the Cortex M0s are very good at conserving power, and have a number of low-power and sleep modes, which make running at these levels quite easy. On the other hand, while Bluetooth 4.0 is low-power friendly, cost and size limits inherent to the watch will probably force the team to do a custom antenna and FCC certification, which is expensive, slow, and painful. I would say the electronics are not too complicated or difficult, but the energy harvesting and design will be tough, and the whole project will be quite arduous. It would be very interesting to see their development plan, and whether they are going for an iterative/modular design, or all-in.