v2.0-android

Major improvements to v1.0,

1. By navigating between tabs, the user can capture videos + IMU data,
   or capture images of a constant focus distance, or preview the IMU data.
2. The user can specify the exposure time, ISO, camera frame size, camera ID.
3. The tap to focus function is corrected,
   now the focus distance can be locked in more Android phones.

v1.0-android

On Android with API 23+.

1. record camera frames at ~30Hz.
2. record IMU data synced to camera frames.
3. tap to focus, back to disable focus.