Hi I’ve just resent this earlier post. Adding that this app is free, and works great on any smartphone with gps. I’ve used it many times I even store my own offline routes produced as described below on my phone. Carrying the battery pack certainly stops the reception running out of power. It even saved me getting totally lost in the Black Forest in Germany. I was using a paper trail guide when we ended up not being where we wanted to be, fortunately I had tracked my route on my phone using ViewRanger and just reversed my tracked route which easily took me back to my car.
Previous posting details for anyone interested.
Just found this thread and personally I now use a smartphone for all my mapping/ gps cycling/ hiking requirements, and for designing my own off road and road rides. I use an app called ViewRanger and have found it to be both efficient and accurate. You register with a psuedonym name, your email address and password, you can download both free and bought map tiles just for the area you want and the maps I use are the open cycle maps. These show mountain trails suitable for bikes as well as footpaths etc. I have used it regularly in the UK, Spain, France, Switzerland and Germany. You can plot your own routes on a laptop at home on a larger screen setting waypoints from the map you can then sync to your phone and download the route for offline use, it gives you loads of information and I set my off road mountain trail routes to warn me with an alarm if I venture 10 meters off my designated route if it is a new route that I have not cycled before. I simply put my smartphone on my handlebars (in a suitable waterproof case and holder) I link the phone with a usb cable attached to a pre charged battery pack on my down tube bag and then have no problem with the phone battery running down in the middle of nowhere. I click on start route and follow the directional arrow on the screen. You can also record a route as you ride/walk if that is your preference. You don’t need the internet just set the app setting on your phone to allow location whilst using the phone. I believe you can also link the route to a friend who can track you while you are riding (although never used this option) Other people can also publish their routes, just be careful, some have not tried them and these can be dangerous. I did one in Spain, off road and the track definitely was not rideable. I came off twice , once with a sheer drop to my right, also always wise to ride with another person in case you get into difficulty. Hope this is all helpful.
