GPS-Trk app on an iPhone may be all you need. The iPhone GPS is good to within 10+/- feet; the app can record and track your position every few seconds, and the aerial imagery is current. When you have a cell signal you can email your track.
Highly recommend Garmin products, marine and land. Intuitive and easy to use.
But I would strongly discourage use of cheap cellphone apps, since nothing more unreliable and frustrating than when you get out of cell range...been there done that.....
While not basic, I use the Garmin Montana with the OnX Hunt chip. There are definitely less expensive Garmin models that you won't groan over a loss. Surprisingly, I've found best online deals from Cabelas' which put them on sale @ 1x/year...keep your eyeout. Good thing about OnXHunt chip (again, don't be tempted by the basic OnX smartphone app - been there, done that, but you do get it also with your state chip as a backup), your son can easily recognized individual private property boundaries and proper respect of land landownership. It also integrates with PC app too for great pre-hunt planning and post mortum/hunt records.
Good luck and happy, safe, ethical hunting!!!