One of the biggest success stories in the world of mobile apps may surprise you: the YouVersion Bible app, which recently announced its 100 millionth download.

The app is downloaded every 1.3 seconds; at any given moment, around 66,000 people are actively using the app. (LifeChurch.tv, the ministry behind the app, recently revealed that 18 percent of its users read it in the bathroom.)

Industry experts say the YouVersion Bible app could be worth around $200 million today—if it was a money-making enterprise—but the app is free, and its creators have conscientiously avoided monetizing the product.

“The goal is to reach and engage as many people as possible with Scripture,” says Bobby Gruenewald, pastor and innovation leader for LifeChurch.tv. “That is all.” (The Atlantic)

Paul Asay has covered religion for The Washington Post, Christianity Today, Beliefnet.com and The (Colorado Springs) Gazette. He writes about culture for Plugged In and wrote the Batman book God on the Streets of Gotham (Tyndale). He lives in Colorado Springs with wife Wendy and his two children. Follow him on Twitter.