Using it with your phone is super easy. Download the Ap, create your account on Garmin, since the device and that's it. I strap it to my pack or bino harness and then just use my phone. Once you pair it, you can pretty much ignore the inreach and use your phone. It will last for days if used sparingly.
For charging get an Anker charger and can recharge many many times.
For charging get an Anker charger and can recharge many many times.