This is a very simple part. Simply press the Start button:
Part 3: Logging
You are in a logging state:
Using the toolbar buttons in the logging state you can (from left to right): add a Waypoint, Stop the logging or Lock the screen.
Waypoints may be used together with e.g. JOSM. At the moment they are just numbered in the order they were added. Assigning waypoint names, associating images and possibly audio comments are planned for future OSMTrack versions. Additionally, at the moment adding a waypoint lacks visual feedback, the waypoint mark is at the first moment hidden below the current location mark. Just don't worry, you will see that a waypoint has been placed when you move further. It is planned to improve the feedback in future OSMTrack versions.
In the locked state all user interaction is disabled except the slider to unlock the screen:
When you press the Stop button the logging mode is exited and a modal view is presented with a summary information about the current track:
The track view in the upper part of the view is pan-able and zoom-able with swipe and pinch gestures, to return to the original scale and center use the double tap gesture.
By pressing the Done button on the navigation bar you will return to the main view. The functions of the Send button on the navigation bar and the detail disclosure button on the track information are described in the section Metadata & Uploading.