Four of us will be driving around Brittany for a week at the end of May. How reliable/useful is Google Maps in Brittany? Is Mappy preferable/worse than/equivalent to Google Maps? Does anyone recommend a different mapping application? And, most fundamentally, how is the cellular service to support the applications? I used (or tried to use) a Garmin device to attempt to navigate around Tuscany six years ago to comical and near disastrous effect. I am hoping to avoid a repeat of that experience in Brittany. I have acquired the impressive Michelin map, but would love a soothing voice along the way to tell me when to take the next right or make a u-turn.