Pentagon App Store

Pentagon App Store

Michael Ossa/U.S. Army via Bloomberg

U.S. Army Capt. Jonathan Springer, an active duty artillery officer, uses his iPhone application Tactical Nav at Camp Blessing, Afghanistan in this February 2011 photo provided to the media. The application Springer built with $30,000 of his savings and a maxed-out credit card a year ago, uses GPS technology and the iPhone’s camera to chart coordinates and guide artillery fire.