Some people write apps for fun. Others for cash.

Then there’s Wilson To, a 25-year-old University of California grad student who’s developing an app to turn a Windows Phone into a weapon against disease. His target: malaria, which kills thousands of young children in sub-Saharan Africa each year.

Today Microsoft awarded To and three other student groups working on life-altering tech projects $ 75,000 to help them commercialize their work or take it to the next stage of development.

The awards, announced this morning at the World Economic Forum in Davos, Switzerland, are part of the inaugural Imagine Cup Grants program—a new three-year, $ 3 million offshoot of the company’s popular Imagine Cup student technology competition, now in its 10th year.

All of the winning projects announced today are impressive—just take a look at the Imagine Cup blog and you’ll see what I mean. One Croatian team used Kinect to help kids with cerebral palsy.  Combining Windows and a Wii-mote, a team from Jordan made it possible for people who are paralyzed to use a computer and phone.

But, as you might expect, the two winning projects involving Windows Phones particularly caught my eye.

The first comes from Falcon Dev, a student team based in Ecuador that’s working on making a Windows Phone translate speech into sign language for kids who are hearing impaired, something they’ve already achieved on a Windows PC. The project is called SkillBox—but you have to see the video to appreciate how cool it really is.

And finally there’s the Lifelens project led by Wilson To.  Using a custom-made app and a tiny lens scrounged from an old CD player, he and his team have made it possible for a Windows Phone to diagnose malaria from a drop of blood. (The add-on lens can magnify blood cells 350 times.) Watch the video below or check out this recent Forbes write-up for specifics. There are already cheap and accurate blood tests for malaria available. But the team thinks a tech-based test still has advantages: Lifelens is being designed to map confirmed cases and transmit real-time results to public health workers, potentially helping them track malaria cases more effectively.

Next steps for To and company: a snap-on case containing the micro-lens. They’re also planning to conduct more lab tests this summer, followed by field testing sometime later. As Business Week reported last year, To eventually hopes to make his app capable of recognizing other blood-borne scourges, such as sickle cell anemia.

“Malaria is just the beginning,” he told the magazine.