I used the MAPS.me app on my Samsung Galaxy A3 2016 last year walking the GR 65 from Le Puy en Velay; and I will use it again in September when I complete the route to Roncesvalles.

The app uses .kml files in conjunction with downloadable maps for each of the departements one is walking through. A very useful app but it has now been developed to include links to various leisure and commercial, rather like Google Maps' local activities, which is not really on the mind of the serious walker.

I sent a request to Viewranger, to find out if .kml and downloadable regional files can be used with their app and am waiting their response. Although accessing the OS or IGN database might be the only source of maps for the Viewranger. Does any other user have experience of this?

The advantage of using MAPS.me is that other walkers will have created routes as .kml files that can be sourced and downloaded from the internet for little or no cost! Once again I would like to hear from any other walker with experience of using .kml files.

As to the issue of battery use, I have found that all other apps need to be disabled to extend battery life when using route software. I also carry an Ankar Powercore 10,000 battery recharge pack - it's very light - which is sufficient to recharge a smartphone several times during the day, and can be recharged at night when I'm in the gite d'etape.

If you want to create and follow routes I thoroughly recommend Viewranger. As well as being able to download OpenStreet Maps or Open Cycle maps for free, you can pay for Ordnance Survey mapping.

I agree. It's a fantastic app. I used it on holiday in spain to locate off road trails in my local area. Very impressed by how accurate it is and by how detailed you can zoom in.
The only weakness with the app is that you cannot make and save a route, unlike mapmyrun.
Other 'issue' is that my phone's battery is quickly diminished when using GPS.

Only having purchased my first smart phone back in January I am still discovering what it can do for me.
I was looking for a way to load maps onto my phone (Samsung Galaxy S5 running Android) that I could access when out of wifi or 4G range, but which would interact with the built-in GPS receiver to tell me where I am.
A colleague recommended maps.me/en/home to provide this service. I downloaded the (free) app to my S5 and have found it to be very useful. Basically, the app contains a world map which can be zoomed to quite a low level. After the installation, it will load the map of the local area where you currently are (location found from the GPS receiver). After this you can zoom in & out to anywhere on Earth. Once you zoom in to a certain level (anywhere on Earth, as far as I can see) and assuming that you currently have either wifi or 4G connectivity (do this in advance of going to an area where you know this won't be available) it asks if you'd like to download the local map. if you do so this will be downloaded. Local maps can be zoomed right down to street level (with street names).
It can be zoomed down to the 10 metre level and in the UK it appears to know about bridleways & footpaths.