Interesting thought about the videos, OLEOSTRUT. A lot of phones also have accelerometers and gyroscopes in them these days. Not good enough for an INS app yet, but it's in your future. One of the reasons they are inaccurate is because of slow refresh rates, but if you had several of them, maybe the data could be integrated.
Oh, don't count much on phones' accelerometers and gyros, because, first of all, phones don't have gyros. They do have angular rate sensors which are good enough for gaming use (like controlling something by tilting the phone), but next to useless when trying to determine device's true spatial orientation. Typical drift of such "gyro" is in the range of 0.1-1 degree/second in steady conditions, and much larger in the presence of vibration, shocks etc. They also have very limited measurement range, and any significant shock throws the phone's accelerometer off scale, making any future integration attempts worthless.
Then, to conserve power, these sensors are powered down most of the time, and even when they aren't, their readings aren't typically logged. A phone ain't an FDR, and chances of recovering something of value from it is close to nil, unfortunately.