In addition to his role at HSPH, Nathan Eagle is CEO of Jana (formerly txteagle), a technology company that has built a platform capable of awarding billions of people with free mobile airtime in exchange for completing surveys or purchasing products.

This arrangement sprang from one of Eagle’s first mHealth projects, helping a hospital in rural Kenya prevent frequent blood supply shortages. He developed a text message application enabling nurses to alert the main blood bank about shortages before they became emergencies. But the project fell flat; the cost of sending daily text messages is a big chunk of a rural nurse’s income.

Eagle responded with airtime compensation, a system that automatically gives users free service in exchange for data transmission charges for each message sent. The scheme worked, and the nurses started texting again.