When the guide starts talking
You come near a place worth hearing and the story starts, with no typing, no stopping the car and no looking at the screen.
Turning the guide on is the last thing you do with the phone in your hand. From there it can stay in your pocket, because the narration follows your journey, and it starts on its own when you come near a place worth hearing.
What makes a story start
Your arrival, and nothing else. You do not type the name of the place, you do not press a button at the right moment, and you do not need to know in advance what you will find along the way.
That holds on foot, by car or by bike, and it holds above all for the place you did not know was there, which is usually the best part of the trip.
Why it speaks on its own
The reason is the safety of whoever is driving, and it decided the whole product. A guide that needs your eyes on the screen is a guide you do not use while driving, and a guide you have to feed addresses to before leaving, instead of making the trip easier, becomes one more chore before it.
What the screen shows while it talks
The name of the place and its description appear while it speaks, for when you feel like looking. You can hear a whole story without touching the phone once, because looking is a choice and not a step.
The full text of the narration sits behind the CC button on the card, which starts off and turns on with one tap. It opens the whole story at once, and you are the one who scrolls, at your own pace.