Here you can find step-by-step instructions on how to record a track with GPX Viewer PRO:
Open main left menu.
Tap Track Recording button.
When red recording icon appears on the right side of the screen tap it.
Select a profile that fits your transportation means.
After starting the recording you have 3 different symbols to use.
Stop the recording.
Pause the recording.
Add a waypoint from your current location.
After stopping recording, you can adjust track details such as name. description, links, location, and file type.
Below is a video showing the following instructions: