Always closes during workouts and loses data – Map My Fitness by Under Armour Review

No matter whether I am running, weightlifting, biking, doing the elliptical or whatever the app closes on me. It may run for 5 minutes or 20 minutes but it always closes. It usually retains the data gathered before it shuts down but that doesn't really help. Seems to have gotten worse with iOS 11.1. I am using an iPhone 6s Plus.
Review by MyHumbleReview on Map My Fitness by Under Armour.