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paywall screen

Inspiration

I wanted a learning app that respects your time. Most "learn something" apps are either endless feeds or heavy courses you never finish. I wanted the opposite: one genuinely useful lesson a day, about five minutes long, the kind of thing you'd actually remember tomorrow. The name comes from "whit", as in "not one whit": a small amount that still counts.

What it does

One free lesson every day. Psychology, science, and everyday skills, each followed by a quick check question.
Streaks and progress. A streak counter and completed-lesson count build a gentle daily habit.
Whit Pro (via RevenueCat). Today's lesson is always free. A subscription unlocks the full archive, so you can reread anything you've finished and catch up on days you missed.
Paywall with real offerings. Monthly, Yearly (with a 7-day free trial), and Lifetime packages, loaded live from a RevenueCat offering, plus restore purchases.

How we built it

App: Expo / React Native with TypeScript, 10 screens (onboarding, sign up, log in, today, lesson, quiz, archive, paywall, settings, profile).
Monetization: the RevenueCat SDK (react-native-purchases) with a single whit_pro entitlement and a default offering. The demo uses RevenueCat's Test Store.
Backend: Node.js + Express + SQLite, seeded with 30 lessons. It handles accounts, streaks, and the paywall rule.
Server-side entitlement check: the app doesn't just trust itself. After a purchase, the backend asks RevenueCat's REST API (with a secret key that never ships in the app) whether the entitlement is active, and only then serves archived lessons. A webhook route keeps subscription status in sync.
Tests: 11 automated backend tests covering auth, the free-vs-premium gating rule, and both billing sync paths.

Challenges we ran into

Native dependencies on a brand-new Node version. The SQLite driver wouldn't compile until I upgraded it.
SDK versions matter. RevenueCat's Test Store needs a recent SDK, so I upgraded react-native-purchases from v8 to v10 and re-verified the purchase flow.
Keeping client and server in agreement. After a purchase, the backend knew the user was premium but one screen still showed the locked state. I fixed it so the UI reads the synced premium status.
iOS layout quirks. SafeAreaView ignores padding on iOS, so form fields ran edge to edge until I restructured the layout.
Designing the paywall rule. Deciding exactly what's free (today's lesson, always) versus paid (everything else, including rereads) took a few iterations to feel fair.

Accomplishments that we're proud of

A complete purchase loop: paywall → purchase → server-verified entitlement → archive unlocks.
Keeping the secret key strictly on the server and verifying purchases there.
A calm, cohesive design system (mauve, deep plum, teal, cream) that makes it feel like a daily ritual instead of another noisy feed.
30 real, written lessons, not placeholder text.

What we learned

How entitlements, offerings, and packages fit together in RevenueCat, and why you verify entitlements server-side.
That monetization is product design: the free tier has to feel generous and the paid tier has to feel worth it.
A lot about the native build pipeline for React Native (CocoaPods, Xcode, simulators).

What's next for Whit

Publish on Google Play and the App Store with real store products connected to RevenueCat.
More lesson categories and a longer lesson library.
Push-notification reminders to protect streaks.
Paywall A/B tests with RevenueCat Experiments to tune pricing.