Your phone is only for data entry form app to devise. It can also be done manually in the rangefinder as well if I remember the product training material correctly.
If you're using the rangefinder you're loading your ballistic profile into the rangefinder/binos via the app. The rangefinder is linking to the scope. You range and the hold over lights up.
What's cool about the system for hunters as well is you can enter a ft lb of energy cut off. So you range and if that distance falls under the ft lb of energy threshold set the reticle will update but it blinks every few seconds to let you know its under the threshold.
Pretty cool tech for hunters and I'm interested to see where it pushes the market.