Already there's a smart phone application that calculates a bullet's trajectory, accounting for wind speed, distance, temperature, altitude and other factors. And soon soldiers will have another app to turn their smart phones into acoustic sensors to help locate snipers.
There's an app that uses a phone's GPS capabilities to track friendly troops, and another that helps troops translate English into Arabic.
Officials responsible for modernizing the U.S. Army say that smart phones and apps - the small but ingenious software applications that make smart phones so smart - will soon be as essential to soldiers as rifles.
It's even likely that soldiers soon will be issued smart phones or other "hand-held devices" when they start basic training, said Col. Marisa Tanner, chief of the doctrine, organization, operational architecture and threat division of the Army's Future Force Integration Directorate.
The Army is moving aggressively to get smart phones ready for active duty.
In March, the service launched an "Apps for the Army" competition in which 100 soldiers or civilian Army employees are competing to develop Army-specific applications by May 15. Designers of the eight best apps will win $2,000 in prize money. Other prizes range from $1,000 to $100. The winners will see their apps deployed.
Separately, the Army's Future Force Integration Directorate is getting ready to issue smart phones to 192 soldiers at Fort Bliss, Texas, in a project called "Connecting Soldiers to Digital Applications."
"We're trying to examine the benefits of putting access to knowledge and information in the hands of soldiers in garrison, in the field and in the theater of operations," Tanner said.
"Sometimes you're only as strong as your comms reach," she said, referring to communications. "Not every soldier dismounted from his vehicle in theater has the ability to access comms readily."
But it's when they're dismounted that soldiers get the best sense of their surroundings. They mingle with locals, observe activity and gather intelligence.
"How do you capture that information?" Tanner asked. "How do you transfer it" to other unit members and commanders? Lately, smart phones have become an obvious choice.
Unlike military hand-held devices, which tend to be expensive, single-task appliances, commercial handhelds are cheap and increasingly able to perform a multitude of tasks.
But for soldiers to get the most out of their Androids, iPhones and BlackBerries, the data they collect and share has to be structured "in a graphic format that is timely and relevant to the dismounted soldier," Tanner said.
And that's where the apps come in.
Drivers in an Army convoy will want an app that can display where roadside bombs have been discovered recently along their route. "We have found three apps that we really like" that do that, Tanner said.
There are mapping apps, maintenance manual apps, training apps, even a "COIN Collector" counterinsurgency information collection app.
For the Fort Bliss project, the Army is making more than 50 applications available to the 192 soldiers who receive smart phones, said Michael McCarthy, the director of operations for the Fort Bliss battle command training complex.
Part of the effort is to find out which apps soldiers find most useful and easiest to use, McCarthy said. If all goes well, the Army hopes to expand the program in January to an additional 2,500 soldiers.
Smart phones have already proven their value as training tools, Tanner said.
When advanced individual training materials were made available via handhelds, soldiers were able to view video clips on how to operate equipment and review classroom lessons outside the classroom. Test scores went up and training time went down, Tanner said.
'A Military Apps Marketplace'
While the Army checks out what smart phones and apps can do for it, the Defense Advanced Research Projects Agency (DARPA) is exploring how the U.S. military can do a better job of buying them.
With a program called Transformative Apps, DARPA hopes to speed up the process of creating and buying new applications.
DARPA Director Regina Dugan said most current Pentagon development and buying practices "do not permit a quick reaction in the face of rapidly changing user needs."
Dugan told a House Armed Services subcommittee in March that she hopes to create "a military apps marketplace" and to develop "a new model for rapidly and effectively acquiring, introducing, maintaining and enhancing software."
If she succeeds, that could represent a real change.
The military often takes five to seven years to develop and buy new technology, said Mark Bigham, the vice president for business development at Raytheon's defense and civil mission solutions division.
Raytheon has already developed applications for the military. One, the Raytheon Android Tactical System, or RATS, lets soldiers designate "buddies" - which could be another soldier or an unmanned aircraft - and keep track of them on a map using a phone's GPS capabilities.
Another lets troops annotate photos and video by drawing on a hand-held screen with a finger, Bigham said.
The company has others in the works, such as an app that will let soldiers share sensor data.
"We talked to guys who came back from the wars" to see what kind of applications they think are most needed, Bigham said.
"This is an exciting new market opportunity," he said of the burgeoning interest in apps.
One caution, though: The U.S. military probably shouldn't count on $2 or $5 apps that are so widely available in the commercial sector.
Commercial applications are cheap because popular ones sell in the hundreds of thousands and volume and competition keep the price down.
In the military market, which is much smaller and more specialized, apps might sell for $50 or $500, Bigham said.