Apple computer now has two sniper rifle software applications for the iPhone and iPod Touch (which looks like the iPhone, but is just an iPod with a big screen and wi-fi capability). The BulletFlight software is available at the iPhone software store, and it performs the calculations needed to account for atmospheric conditions (wind, temperature, humidity, altitude and barometric pressure) for long range shooting. The output tells you how many clicks to adjust your scope to make the shot more accurately. Before use, you input basic data like rifle type and bullet weight.
Now a highly experienced sniper can do this in his head. There are similar dedicated devices that cost about $7,000. But BulletFlight is affordable, does the job and appeals to inexperienced snipers, hunters, recreational shooters and those who are just curious. The software costs $12. If you want to actually use it, you need to buy a protective case ($50) for the iPod, and a device ($25) that attaches it to the rail found on most sniper rifles and high end hunting rifles. So for shooting purposes, the entire kit costs you about $90. An iPod Touch (8 gigabyte version) sells for under $200.
There is some concern that the light from the iPod Touch screen might give away the snipers position at night. But you can set the light level on the Touch, so it probably won't be a problem. Besides, you are using BulletFlight for long range shots (300 meters or more), so the light from the display won't be a major problem. Or it shouldn't be. Time will tell. IPods are popular with the troops. Not just for the music and videos, but also for foreign language translations. This uses special software developed for the U.S. Army and distributed to troops in Iraq and Afghanistan. Soldiers and marines are big users of smart phones (like the iPhone) and new ideas. A lot of troops are going to try out BulletFlight, even if they aren't snipers.