Arcep maps out the status quo with monreseaumobile.fr:

Arcep is publishing new coverage maps that deliver a four-tiered evaluation. Tested in the Nouvelle-Aquitaine region during the first half of the year, this more detailed snapshot is now available for the whole of Metropolitan France. These maps have also been incorporated into the application launched in March: monreseaumobile.fr. At a time when mobile connectivity has become a vital issue for every region, by enabling an accurate diagnosis, this tool can help in drafting targeted public policies.