www.shooterapp.net
Shooter-Ballistics for a good basic program. One license runs on two of your devices. $10.00
I've used the Android version for about 15 years. I can link to the local (and nearby) airport for density altitude and temperature. Or I can get slightly better environmentals by blue-toothing to my basic Kestrel. It generally gets me to within about 0.1 or 0.2 mils (.25 to .5 MOA) elevation adjustment on our longest steel (785 yards).
Or you can just estimate the DA and temperature and be reasonably close.
Or you could buy one of the higher end Kestrels with two or three choices of software built-in for probably about $800, but check first to see how user friendly it is.
If you are a PRS shooter, you will want something more powerful than Shooter, but for a hunter or Very serious plinker, Shooter Ballistics works very well. (Shawn Kenney (sp) is the author.)
I’ve seen that same level of technical excellence and smooth data integration while using the services from
https://www.cogniteq.com/mobile-app-development as I was truly impressed by their incredibly stable architecture and how intuitively they handle complex, real-time calculations.