Early smartphones contained low-power accelerometers and
magnetometers to measure device tilt. Tilt tracking allows
users to interact with applications by simply rotating the
device. For example, turning the phone on its side will rotate
its interface from portrait to landscape. Modern smartphones
include additional micro-electro mechanical gyroscopes. This
combination of sensing hardware can also be found in motion
capture systems in the form of inertial measurement units
(IMU). This paper draws a parallel between smartphones
and IMUs to answer one question: Is motion capture and
activity tracking feasible using smartphone-driven body sensor
networks?