How Hallow Tests 500% Faster to Reach More Users with Helium
6min Read
Hallow is one of the most beloved prayer apps in the world. Here's how they used Helium to dramatically accelerate experimentation and serve more users in more markets.
Zac Crippen
Head of International Growth, Hallow
Context
Hallow's mission
Hallow is one of the most popular prayer apps in the world, serving millions of users across dozens of countries on both iOS and Android. Their mission is simple: make prayer accessible to everyone.
But "everyone" is ambitious. It means users in São Paulo and San Francisco. People who've prayed their whole lives and people just getting started. And reaching all of them requires the kind of growth that compounds — expanding into new markets, adapting to local needs, and reinvesting in the next wave of users.
Hallow's team had no shortage of ideas for how to serve more people in more places. The question was whether they could test fast enough to keep up.
When testing can't keep up with growth
Every experiment required engineering time, app store submissions, and weeks of waiting. Running a single paywall test meant pulling engineers away from the core product. Running tests across multiple countries simultaneously was a project in itself.
The gap between the team's ambition and their ability to test was growing. They needed a way to experiment that matched the pace of their growth — not one that bottlenecked it.
Managing paywalls separately on iOS and Android added another layer of complexity. Duplicated effort, divergent experiences, and more surface area for things to go wrong. The team needed to unify their approach across platforms so they could grow without scaling overhead linearly.
8 experiments in the first month with Helium
Hallow integrated Helium and the difference was immediate. The team could launch experiments without writing code, without waiting for app store review, and without coordinating across engineering sprints. An idea in the morning could be live with real users by the afternoon.
Helium also unified Hallow's iOS and Android paywalls into a single workflow — same tools, same experiments, same data, regardless of platform. That meant a growing team could do more without the overhead growing proportionally.
"Helium's laser focus on customer success is unlike anything we've experienced with other teams. The dedication to getting the job done — staying up in the middle of the night to troubleshoot with us — it's on another level."
Within one month of launching, Hallow ran 8 experiments across nearly all of their global markets.
"Launching eight tests in a span of five weeks is probably like a 500% increase over what we could do previously, as far as just pace of testing."
25% more users in Brazil and a scholarship program launch
One of Hallow's early experiments in Brazil drove a 25% increase in users signing up and using the app. A quarter more users in a key growth market, unlocked by a single experiment that took minutes to launch.
Hallow also used Helium to seamlessly launch a scholarship program — making the app accessible to users who otherwise couldn't afford a subscription. It's the kind of initiative that's core to Hallow's mission but historically difficult to test and roll out quickly.
These wins compound. More users in more markets generates the growth that funds continued expansion — more languages, more content, more platforms. For a team with Hallow's ambition, each experiment doesn't just improve one metric. It strengthens the foundation for everything that comes next.
Reaching more people, faster
Eight experiments in one month. Nearly all global markets. A 25% user increase in Brazil. A scholarship program live and running. Unified iOS and Android paywalls.
The growth Hallow has seen since working with Helium has been significant — and it's enabled them to reinvest in serving even more users. When you can test faster, you learn faster. When you learn faster, you grow faster. And when you grow, you can do more of what you set out to do in the first place.
When testing takes weeks, you're conservative — you pick your bets carefully and hope they pay off. When testing takes minutes, you can try everything, learn from everything, and compound those learnings into the next wave of growth.
That's what faster testing actually means for a team with Hallow's mission: the ability to grow sustainably while staying focused on what matters most — making prayer accessible to everyone.
