There is an App called "avenza PDF maps" you can download all the topo maps in the USA to your phone for free. Basically you figure out what quad map your area of interest is and download it. The amount of quad sheets you can download depends on the amount of storage your phone has. These maps are stored on your phone so when you go in the field you don't need service to look at them. These are like having a paper map that tells you exactly where you are on the paper. The GPS on your phone works like any Garmin GPS so you don't need cell phone signal to see where you are at. The main reason google earth ect... doesnt work in the field is cell signal to load the background imagery.
You can mark points, mark trails in and out, plot photos in the location they were taken, measure distances, measure polygons, email points to your hunting buddies to use in their avenza maps. In my opinion you can keep your garmin in your backpack. This thing will do everything it can and more! Keep the garmin as backup though in case your phone dies.
Yeah, may have to check that out myself. I've been using "my free topo.com" and it does what I need. I like being able to switch between topo and satellite and back, helps pin things down. Where I usually hunt, the cell service thingy hasn't been an issue, yet!:wink: