A regular, actual recording in myTracks on iOS does not stop automatically. But there is a limitation of iOS that can kill myTracks if it is running in the backgound. If there are other apps running on the iPhone that need much resources (CPU and/or RAM) then iOS can stop apps that are running in the background. As a developer I cannot avoid that. But myTracks can send notifications if no new data has been recorded for some time. To activate that tap the (REC) button and tap 'Settings'. There you will find 'Notifications'. Select an appropriate value there. Please also make sure that notifications are allowed for myTracks in the iOS settings app. After activating this feature you will be notified if myTracks didn't record a new track point during that time period. Then it is time to open myTracks again and the recording will continue.