The air plane mode available in the app will enable you to access at any time to your layers and itineraries, wherever you are, including the areas without network connexion.
You want to realize an itinerary on a place where you know the network connexion is not good ? Don't worry, Trail Connect app is here for that. You just have to think before about downloading the data before your activity, by clicking on caching track. This action will allowed you to download on your mobile phone the itinerary data (track, point of interest, description...) and the layers linked. You will have the possibility to get several layers at the same time, if you want during your activity to go from a layer to another.
You don't have a specific track in mind but you know you will make sport in a specific area without network connexion ? Don't worry, Trail Connect app is here for that. Thanks to the map module, create a geographic extent of your choice and click on place your track in cache. You can geolocate yourself at any time on the layer, and save the itinerary you want to follow, even without network connexion.