Works great, doesnt kill battery
I use this on ferries and trains as I like to know speeds, has knots for water travel. Great for riding shotgun when you cant see the speedo to know how fast the wife is going. Great real time with minimal delay, free version has no ads or pop ups. Does not kill battery. Used for 80 minutes and battery went from 92 to 85 on iPhone 6. Built in GPS as good as google maps. Very happy with this.
Helmutwang about
Speedometer 55 Start. GPS Box.