The American public is becoming less religious and less likely to attend church than in decades past, according to research like the Pew study released last month. But for Christians looking to spread the faith, there’s been a recent bright spot: apps that can put the Bible in the pockets of millions, plus open the door for new and potentially more habitual forms of prayer and meditation.

"Jesus met people where they were at and then drew them really deep into understanding the truth of God," said Neil Ahlsten, who left Google last year to found the app Abide. "We’re creating liturgy that people can consume whenever and wherever and however works for them. It fits the modern life." Ahlsten has heard from many users who check Abide in bed — first thing in the morning and right before they go to sleep — as many secular people do with their phones. Christians have been praying at morning and night for millennia, but it turns out the tradition fits comfortably with habitual smartphone use.

YouVersion was one of the first Christian apps and remains one of the most popular — and one of the most popular apps, period — but it almost didn’t make it into the App Store. Before it was an app, YouVersion lived online as a website created to "help people better engage with the [Bible]," said Bobby Gruenewald, the app’s founder. The site was on the verge of being shut down in 2008, when an early mobile version saw a spike in traffic with the adoption of smartphones. The team behind YouVersion put together an app for the App Store launch, and it had over 80,000 downloads the first day alone. Since then, it has been downloaded nearly 200 million times and consistently lands in the Top Charts section of the App Store.

"It’s not always practical to carry a print Bible in my purse," said Nish Weiseth, a Christian author and speaker. "It’s usually stuffed, so throwing in a Bible is just one more thing to dig out. I’m on my phone a lot throughout the day anyway, so having the entire Bible readily available to read on my phone is really handy when I’m out and about." This refrain was common among people talking about their devotional apps: they're convenient. Just as most of us no longer get our news from the delivery boy, those who read the Bible are opening an app rather than carrying the physical thing.

Phones also enable forms of devotion beyond simply reading a digital version of the Bible. Want to get daily texts from Jesus? There's an app for that. Your daily Bible reading can be delivered to your inbox, and if the faithful don't feel like leaving home on Sunday mornings, they can stream church services from one of dozens of apps. Confession guides users through the appropriate prayers of penitence for the sacrament of confession; Prayer Notebook lets users sync their prayers across devices; and Neu Bible is a minimalist take on the Holy Book for the design-minded. (Full disclosure: My father, who is a pastor, has consulted on the development of a religious app called SoulPulse.)

Behind a number of these apps is the Christian concept of spiritual formation, the idea that if we undertake certain practices or disciplines, Christians can become more, well, Christian: kinder, gentler, more full of joy, and so on. Books and Bible studies have been written with this goal in mind for centuries, but now spiritual formation efforts have moved online and into the app store. Some, like that "Texts From Jesus" app, appear to be just another flashy version of religious kitsch, like an app-ified "Footprints" poem. But others seek to use the ubiquity of personal devices as an opportunity to encourage spiritual growth.

The YouVersion Bible app is on 197 million phones and is available in 799 languages. Backed to the tune of $20 million by Oklahoma City-based Life.Church (a megachurch that streams its services online), YouVersion features reading plans, goal-setting abilities, and a built-in social network.

Tamás Kádár, a 26-year-old Hungarian IT consultant living in Sweden, uses YouVersion to follow along in church and "whenever I need to look up something, especially with different translations, in different languages." Within the app, you can overlay Bible verses on top of nature images and share the resulting meme with your Twitter followers, Facebook friends, or on the app's home feed. The YouVersion Bible, also comes stocked with hundreds of reading plans, from the devotional to studies for the family to topical studies, like "Find purpose in your work." These plans often come at the result of partnerships with other apps or publishing houses, which can feel a little sponsored. For instance, the iPhone game Gun Bros once featured YouVersion as an app that players could purchase to gain more in-game currency.

Some Christian apps have encountered serious problems: Instapray, the Peter Thiel-backed app that allowed users to share their prayers with each other on their proprietary platform, sent an email out to members in October saying that they are "no longer able to sustain the costs" associated with running the app and asking members to subscribe to the Instapray Reading Club for $9.99 a month.

Apps like iDisciple charge their users a monthly fee for access to premium content. (In this case, "premium content" means Bible-reading plans, shareable prayers, and teachings from well-known Christian leaders.) Many Christian apps charge a fee to download. Still, it’s a hard market to succeed in financially. As Amy Keyishian wrote at Recode earlier this year, "it’s next to impossible to monetize a prayer app. Therefore, the only logical explanation for Thiel’s involvement is that it’s a sort of tithing," or giving back to the community.

Neil Ahlsten worked in business development at Google from 2007–2014, but left when he felt God calling him to put technology to use for the church at large. "What if you assume that the Bible contains insights into human behavior?" Ahslten asked himself. "Can we design experiences around those behaviors that help people practice them better in modern life?" Ahlsten and his team (some of whom also came from Google) surveyed Christians about their "user experience" of the Bible, and found that the top problem modern-day Christians had was that they weren’t sure how to pray. "Basically we're creating liturgy that people can consume whenever and wherever and however works for them," said Ahlsten. Abide provides users with daily prayers based on Bible verses and the ability to set prayer reminders. The prayers themselves are accompanied by gentle background music, and cover topics like "Thankfulness," "God's Plans for You," and "Unity in Love."

In many ways developers of religious apps are no different from their secular counterparts. Everyone is trying to take a desired habit (in this case, prayer or scripture reading) and make it more painless, easier, and more deliverable. The word "frictionless" pops up often. YouVersion will send you a gentle reminder if you haven’t made much progress on the plan you selected, and give you a few helpful hints for keeping up. Abide provides an array of recorded prayers users can listen to so that they can learn how to pray.

Evangelical Christianity is very interested in cultural relevance. One of its flagship magazines is actually called RELEVANT; church services have been streaming online ever since the technology was made available; pastors trumpet their love of U2 and Sufjan Stevens as badges of being with it. With the demise of Christian separatist communities and the crumbling of the moral majority's denunciation of culture, Christians are increasingly adapting to existing cultural norms, in this case, those of the tech sector. In a 2014 New Yorker article, Casey Cep compared this phenomenon to a "FitBit" for the soul, and she’s not wrong. In the quest to live quantified lives, we can set reminders for ourselves to exercise, eat well, and now, to pray. And it makes sense, if we think of the spiritual life as a discipline, that it could benefit from some of the same techniques that have reimagined the way people approach fitness

The people behind many of these Christian apps have set out to examine the UX of the spiritual life: Where are there bugs, and why do they happen? What features are users missing? How can we hack prayer? Quantifying spirituality makes some people (understandably) uncomfortable, and the latest technology will always have its skeptics. But it will also have its evangelists, and they’re ready to share the good news.