With the free Strelok, there are 5 different loads you can save for each rifle. The pro version has more features. For a basic ballistics program, it's pretty nice, and I like the reticle feature as well. It has a ton of reticles and scopes in the database, with the reticle pictures. It will show holds on the reticle for the range and wind conditions you enter as well.
Lapua also has a good ballistics program for the Android.
I have them both, and I also use Berger's Ballistic Program on the PC's and Laptops. I like it for 500yds and further because I can enter G7 data, which is the drag model function more appropriate for boat tail bullets, and boat tails are all we shoot at distance anyway.
Make sure you know your barometric pressure and enter it accordingly for your trajectories. I shoot often at sea level, 4400ft ASL, and 6600ft ASL. Those are huge differences in barometric pressure, as the air is less dense as the altitude gets higher, meaning bullets fly flatter.