On the SLP app homepage - select a camera
Click on the playback icon (looks like a clapperboard used in films)
From playback you can move through the timeline, select another channel to playback, change the date & time, etc.
Start the backup process by clicking the image of the camera and then click the playback icon with scissors.
From here, you can adjust the length of footage on the timeline and click start download.
These steps save the backup footage into your files.
Go back into your homepage and click the icon in the top left corner > Files > select footage > download footage direct to your phone.
Video below for reference.