Chauffeur shows a live screen while you drive. Please read this part.
The live screen is designed to be glanceable — large numbers, colour coding, lights that can be read at the edge of vision. That is a design goal, not a permission. Reading a phone while driving is dangerous and in most places illegal, and no amount of careful layout changes that.
Mount the phone where it does not obstruct your view. Set the screen up before you set off. If you want to know how a drive went, look afterwards — that is what the whole review side of the app is for.
The score measures how comfortable a ride would be for a passenger. It is not a measure of safety, competence, skill or legality, and it must not be used as one.
A late emergency stop is exactly the right thing to do and will score badly. Driving slowly in the wrong place is dangerous and will score well. The app cannot see the road, the traffic, the weather or the child who ran out.
If improving a number ever competes with driving appropriately for the conditions, the number loses. Braking gently to protect a score when you should brake hard is the failure mode this app could plausibly cause, and it is worth naming plainly.
You are responsible for complying with the road traffic law where you are driving, including any rules about mounting or interacting with a phone.