Ok, so you have the basic 5700, not the Elite or X?
If so, it can only hold 3 guns at a time. You can build an assload on the app, but you'll only be able to load a max of three unless you upgrade.
Go to the App store or Play and DL the App, then
Go to Kestrel's site and go through their "schoolhouse" and their virtual classes.
The Kestrel Ballistics Schoolhouse is your one stop to learn how to use a Kestrel Ballistics meter, download articles and manuals, and see the latest FAQ's.
kestrelballistics.com
Kestrel Ballistics handheld weather meters will help you hit your long-range target on the first shot using the built in ballistics calculator and weather sensors.
kestrelballistics.com