the thing abut these phone GPS apps is that your phone battery won't last very long. Fine for a day hike, but beyond, you need to lug solar charger and other stuff along that's not always reliable.
I never cared to look into what is possible with these my phone, as I can't keep mine running on standby for much more than 24 hours. Fine for short hikes, but for the hikes I do, where there's no charger for a week or more, I need a GPS with interchangeable batteries that last as long as possible.
I haven't really looked at current models in almost 10 years now, since my Garmin 60csx works fine for what I use it for. It is indestructible and runs for two days on a pair of light Lithium AAs. I bought the California 24k topo map for it years ago and that's almost more detail than you need.
You can find these units on ebay for under $100 if lucky, but many are selling close to what I paid a decade ago. The new version of it is the Garmin 64st. not much has changed, and the price is still up there. These things don't work much better than a phone when it comes to GPS reception, but they are bulletproof and efficient.
My unit has seen about 50,000 miles on a dirt bike in all kinds of weather and dirt, about 10 summers in the Sierra with probably 6 months total in the outdoors, plus many thousand miles on a bicycle. I also use it in cars on longer trips away from home, so I'd say it has been tested thoroughly. If it ever dies, I'll try to find another one just like it.
