After more than two years worth of apps for the iPhone, not to mention other handsets like the Android, few applications come as a complete surprise. But one app I looked at recently definitely fell into that category — if only because it has been installed close to 10 million times, and has millions of regular and devoted users, but hardly anyone in the tech press ever writes about it. It’s called YouVersion, but it’s better known as “the Bible app.”

Yes, the Bible has an app. No, it was not delivered to anyone on a mountain, and there were no burning bushes involved. And yes, it’s had close to 10 million installs, according to Bobby Gruenewald — a pastor at Lifechurch.tv, a high-tech church based in Oklahoma (with branches in seven other states) and the brains behind the Bible app. Gruenewald was involved in the tech industry before he joined the church (he had a web-hosting company in the 1990s he eventually sold) so the idea of using the web and mobile to help people connect with the Bible seemed like a natural, he says.

The app provides an easy-to-read interface to the Bible (obviously) in more than 40 different versions and 22 different languages, but has social features and other interesting functions built-in as well: Users can share their favorite passages by posting them to their Facebook wall or sharing them on Twitter, and Gruenewald says there have been half a million such tweets over the past year. Users can also choose from a number of pre-set reading plans (read the New Testament in six weeks, etc.) then track and share their progress much like runners do with Runkeeper.

It started with a website in 2007, where anyone who was interested could find Bible passages and reading plans, and then was followed by a mobile version of the site in 2008 that looked better on smartphones. When Apple launched the app store for the iPhone, the church had a simple version of its app available the first day, and since then, there have been repeated iterations. Interest in the app continues to increase at a fairly rapid rate; Gruenewald says YouVersion is seeing about a million installs a month (many of which, not surprisingly, happen on Sunday).

The app also allows pastors and priests to put together passages with their notes, links to content, and even polls that users can take on various issues — as well as an interactive feature that allows them to solicit names of parishioners that should be prayed for. The app uses geo-location to show users if a nearby church has a lesson plan or other content available so they can download it. Upcoming features include support for text, audio and video notes associated with specific passages, Gruenewald says — and possibly even Foursquare-style badges.

It’s fascinating to see the traditional technology approach of a mainstream app used for something like YouVersion, and how quickly it seems to be taking off — not surprising, perhaps, given the viral effect that seeing another church-goer using the app would have. In terms of the breakdown of users, the pastor says that iOS devices (iPhone and iPad) account for about 5.6 million of the installations, while Android and BlackBerry are more or less evenly matched at about 2.4 million — although the number of Android users is growing quickly, he says.

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