It's the question all apps developers have to grapple with: to charge or not to charge? Paid apps rake in the revenue, but have to battle with limited demand; free apps get the downloads, but how do you generate the revenue?
There is a middle way: in an effort to both attract users and boost revenue, a growing number of free apps are now offering in-app purchases – known as the freemium model.
It's an idea that has already gained a lot of fans. In January 2014, some 79 percent of total revenues on Apple's App Store were generated in the U.S. by freemium apps, according to analytics company Distimo. By contrast, paid apps generated just 17 percent of revenue over the same month.