In reply to Rob Exile Ward:
Agree with Rob. It’s worth checking out the Viewranger app. It’s free, and excellent with good detail, so have a look. Already has a lot of standard routes marked up. Really easy to add a route, just a couple of minutes. Options for sample times to record you’re route real time as well; longer sample time, less battery use. Depends what you want I guess. I take an ‘old’ phone, no SIM card, (Motorola G4, so still not bad!) for ‘emergency use’. I take it ski touring in N Norway / Sweden with routes already loaded. But I keep it switched off and the battery will last months like that. I used it in earnest a month ago. Was 6km from the hut, no tracks, low cloud / very flat light and flat terrain so virtually no features to help with compass bearing. Occasionally I switched on the phone and ViewRanger within about a minute had confirmed my precise location relative to my preset route, then switched it off again. Was pleased I was essentially on track each time, but it was very reassuring. Hardly any battery power used, and it was -10C. Just in case I also carry a power bank. If you do like this, suggest look at Motorola moto G7 power. Got massive battery life.