I would almost say the issue is the usable space on the phone as well as older iOS. When the apps quit like that, it is usually do to memory issues, or lack thereof. The 5C is near it's effective end of life. Not saying that is the only issue, or there isn't an issue with the app, just pointing out the technology is fading. At work, we've pulled all the old iOS devices (iPhone 6 and previous models) because of both security issues and slowness. I dont know if you have an upgrade coming, but that would probably be your best route. If you can clear up some space on the phone, try again. Maybe it just needs some scratch space to store the recorded route.