The use of a phone as a GPS in the back country is not only practical, but offers big advantages over a dedicated GPS device.
This page describes the hardware and software that I use. As my phone is Android, I cannot comment on Apple phones.
A good phone for GPS does not have to be the latest. I use the Acer Z630, available from Walmart or Costco for $200 (as of 2016-08). This phone has a large display. This is a big advantage for use as a GPS as much surrounding terrain is visible, allowing for orientation with respect to neighboring terrain. Other important features are a compass sensor, a good battery and Assisted GPS (A-GPS) which finds satellites more quickly.
Advantages of a phone for GPS
- large display - the Z630 has a 5.5 inch (720 x 1280 pixel) display, as compared to the Garmin 60csx which has a 2.6 inch (160 x 240 pixel) display
- fast pan and zoom - much faster than the Garmin 60csx, which redraws the screen each time
- tracks are stored in open source format (.gpx), rather than the Garmin proprietary format (.gdb)
- no need to use special software to retrieve tracks from the device
- the phone is a general use computer, providing a camera, bird apps, flower apps, etc.
- not waterproof - the phone must be kept in a plastic bag and is not easy to use in the rain
- more fragile - must be more careful where it is kept; use a screen protector
The Acer Z630 has a 4000 mAh battery which is large for a phone. I have used it for full days and returned with 70 percent battery remaining. Additional battery life can be had by turning off wifi and bluetooth.
The phone can be used over a number of days through the use of a power bank, a battery that allows the recharging of phones through the micro-USB charging port. An advantage of the power bank is that it allows recharging without turning the phone off. A power bank is similar in weight to spare batteries for a GPS device.
When tracks are recorded with both a phone and a GPS device, there is little noticeable difference. There is a limit to handheld GPS accuracy, as a group of GPS users will notice when they compare stats at the end of a trip. Canyons and walls especially compromise accuracy, probably due to reflection of the signal.
GPS Phone Apps
I use Backcountry Navigator (BCN). There is a free version and a paid version, so you can try it out for free. The free version has all of the functionality - I used it for a while - but uses a small part of the screen for ads. I have found Backcountry Navigator to be quite satisfactory so I have not looked at other GPS apps. BCN is very good. My only complaint is that it treats routes the same as tracks.
Normal use of the BCN app is to download maps of the area you are hiking, before you go. Good sources include Canada's Toporama. I have not explored other map sources.
The alternative is to use pre-built atlases - basically databases of maps. These can be placed on the phone SD card. BCN allows atlases to be loaded from the SD card.
I built 5 atlases (to keep the file size below Android's normal file size limit - 4 GB for FAT32). They cover the mountains from Jasper to the US border, plus one for the Calgary area. In total, they are around 20 GB, so you need a 32 GB SD card in the phone. These were built with MOBAC from Canada's Toporama.
The Mobile Atlas Creator (MOBAC) allows atlases to be created from various maps sources. The program is written in Java and so will run on Linux, Mac and Windows.
MOBAC is run by choosing a map source, selecting the area to be included in the atlas, then letting it run. A large atlas includes a significant volume of data, so the program will require many hours for the download. Atlases for BCN use the SQLite format.
The program interface can be a bit confusing. It is best to start with a small atlas. I found that it missed map tiles on the first run, but it got them all on the second run. All maps are kept on disk, so they are not downloaded a second time.
The GPS Exchange Format (.gpx files) has become the standard for saving GPS tracks, waypoints and routes. Garmin devices use Garmin GPS Database (.gdb) files. The Keyhole Markup Language (.kml files) is used to define map features, usually in conjunction with Google Maps, and can also be used to store tracks.
Bow Valley Software Tools
Bow Valley Software has pages available for creating routes and for viewing tracks.