Hi, I have a problem which comes on my IPad Mini 4:

As long as SD is on the screen, all is fine. But if I change to another program, SD stopps logging after a few minutes. Any ideas ho to get SD running in the backround?

This, this is a very different problem to the original post. Your problem is your GPS signal dropping out and no longer being available to apps like SkyDemon. This is not something over which we have any control.