I have both isnipe and Applied ballistics mobile. I snipe is a little easier to use, but i really like the ballistic calibration feature of the AB app, making it much more accurate as your projectile goes through transonic. With isnipe i couldn't get data to match up to field DOPE no matter how much i played around with the BC and velocity it would just end up throwing my closer range values way off. Its like A.B. app uses some kind of decay formula that changes your BC as velocitiy decreases and lines up the data perfectly with what i see downrange(after i do the calibration inputs). Litz is truly a mad scientist-ballistician genius who seems to have it all figured out. Two thumbs way up for AB. Its a little pricey, but well worth it!