In this blog, Paddle looks at the Cal AI App Store Saga. Why were they removed from the App Store? What did it teach us about Apple’s App2Web T&Cs? And how can you keep your app compliant when shifting revenue through the web.
When Cal AI, a leading calorie tracking app, was removed from Apple’s app store in 2026 the narrative that followed was predictable.
Cal AI had been running external payment flows, routing subscribers to a web checkout instead of Apple's in-app purchase flow. Many thought the removal was just another round in the long fight between developers and Apple over subscription revenue in a post Epic vs Apple world. But the reality was much more nuanced.
For anyone building App2Web, this nuance matters a lot. After almost a year of external payments the industry was full of genuine uncertainty. Developers knew external payments were allowed in the US, but working examples of what compliant actually looked like were thin. Cal AI pushed the limits and gave us our clearest signal yet.
In this blog we take a closer look at the app, the violations that led to their removal and what the whole episode taught the market about App2Web.
Understanding Cal AI
To understand what happened, you need to understand Cal AI. Cal AI was built by Zach Yadegari and Henry Langmack. The pair met in 2023 before launching the following year and scaling to $50M ARR, with 15 million downloads. Category leader MyFitnessPal soon came knocking, acquiring the app for an undisclosed fee in January 2026.
Cal AI are widely seen in the app space as distribution innovators. The product is built around TikTok, refined so it can be wholly demonstrable in a ten second video. From product, distribution, and, as it later turned out, testing what Apple would and wouldn't accept in a monetization flow, Cal AI is a company that moves fast across every dimension.
A quick recap: App2Web
App2Web is the shorthand for a specific implementation: a user inside your app hits a paywall, taps a button, gets redirected to a mobile web checkout, pays, and gets sent back to the app. The subscription renews on the web going forward.
The economics here are meaningful, Apple charges 30% on in-app purchases (15% on the Small Business Program) while selling on the web costs around 5-6% in processing fees. That's a roughly 24-point margin delta and when that gap gets reinvested into user acquisition, the compounding effect is significant.
One important constraint: this is US-only. The EU operates under DMA rules with a separate framework. While other jurisdictions look set to open up, at the moment the US remains the most workable market to run this motion.
Where Cal AI went wrong: three violations
Cal AI pushed the limits of what was compliant on App2Web, but what exactly are those red lines? Here’s a quick breakdown from a recent webinar on App2Web optimization with our VP of product Lucas Lovell.
Click here to watch the webinar in full.
Violation 1: They removed IAP entirely (Guideline 3.1.1)
Cal AI implemented a full Stripe payment flow inside the app and removed Apple IAP as a checkout option altogether. Under the post-Epic rules, this is the core error. Non-reader apps must still offer IAP alongside any external payment option, but you can add a web checkout next to IAP.
The reader app exemption is worth understanding here: Netflix, Spotify, and apps providing subscription access to books, audio, video, or music can go external-only. Cal AI is not a reader app, so that exemption didn't apply. You must offer IAP to customers, Cal AI removed it entirely.
Violation 2: Deceptive billing design (Guideline 3.1.2c)
The paywall displayed a weekly-calculated price prominently, rather than the actual charge amount. A free trial toggle obscured the automatic renewal terms. This dark pattern violation compounded the case against them.
Violation 3: Manipulative tactics (Developer Code of Conduct 5.6)
If a user declined the first subscription offer, the app served a second, different subscription flow, which resulted in user confusion, negative reviews and high chargebacks, further justifying Apple’s response.
What were the repercussions?
Apple pulled Cal AI from the App Store in mid-April 2026. At the time, it was #4 in Health & Fitness. Cal AI fixed the issues and the app was reinstated four days later.
What the saga taught us
Cal AI ultimately did the industry a favour. The period between the Epic ruling (May 2025) and April 2026 was marked by some confusion, developers knew external payments were technically allowed in the US, but they didn't know what "compliant" looked like in practice.
The guidelines had changed, but implementation examples were thin. The consequences of getting it wrong, App Store removal, were severe enough that many founders simply didn't move. Cal AI pushed hard enough that Apple responded publicly, with specific violations cited.
How to implement App2Web correctly
1. Keep IAP in the checkout
Apple IAP must remain available as an option. You can add an external web payment route alongside it, you cannot remove IAP.
Strava's implementation shows the model clearly: "Subscribe Annually" takes users to a web checkout; "Pay In App" routes to IAP. Both options are visible. Both are accessible. That's the standard.
2. Use an external browser, not an in-app web view
External payment links must open in Safari or the device's default browser. An in-app web view blurs the line between native and external, Apple treats it as an ambiguous implementation, so it’s best to avoid.
3. Resubmit for review
Adding a button that redirects to an external checkout is a material change to your monetisation experience. It requires a new App Store submission. This is not a technicality you can skip.
4. Transparent pricing, no dark patterns.
The web doesn't have a governing body enforcing standards the way Apple does on the App Store. That freedom is not a licence to mislead. Show the actual charge amount, not a weekly equivalent of a monthly price.
Make trial auto-renewal terms unambiguous. Don't serve a second subscription flow after a user declines the first. Deceptive patterns spike chargebacks, damage retention, and attract increasing regulatory attention globally - well beyond App Store consequences.
5. Make the handoff fast
Users are on their phones. The redirect to Safari and back needs to be near-instant and reliable. A broken return journey - where someone pays on the web and lands back in the app with no confirmation - kills trust and conversion in one move. Treat speed as a KPI, not an afterthought.
6. Lead with wallet payments on the web checkout
Apple Pay and Google Pay must be prominent. A full card entry form on a phone is friction most users won't tolerate. Prioritise wallet payments in your checkout layout.
7. Keep pricing consistent across app and web
Different prices in different places erode trust and create churn reasons. Keep them consistent.
8. Tell users what's about to happen
Before you redirect to Safari, say so. A single clear line "You're being taken to our website to complete your purchase" is enough. Don't silently hand users off to a browser.
Grow beyond the app store, compliantly
App2Web is a real opportunity. We know the economics are meaningful and the guidelines are becoming less opaque thanks in large part to Cal AI. But challenges and complexity remain. For apps thinking about experimentation, a partner that helps you concentrate on what matters most is essential.
Paddle's partnership with Helium is the only purpose-built App2Web solution that combines AI-native paywall optimization with a fully integrated Merchant of Record, so mobile sellers can move more revenue to the web with confidence, protect conversion, and focus on building a product customers love.
