When I tap this big round button I can see on the screen that tracking works good - I can see speed and altitude are changing. But as I lock my phone - tracking stops. I tried not to lock my phone by myself, but after a while phone comes in sleep mode and tracking stops the same.
And one more thing - is it possible to change measure units? In my country we use meters and km/h
I'm using Xiaomi Redmi 3S with MIUI 8.1.4