Why Paying Members See a Paywall in Airplane Mode — Keeping RevenueCat Entitlements Alive Offline
Open the app on a weak connection and a paying subscriber sees a paywall flash for a second. Here is how RevenueCat's customerInfo wavers on an offline launch, and a cache design that keeps entitlements valid with a trust window — written as working code for an Expo app.
When EAS Update Ships but the Bug Won't Die — Why OTA Stalls Silently, and How I Operate Around It
EAS Update can succeed and still fail to reach a slice of your users. These are field notes on runtimeVersion drift, updates that publish but never get adopted, and choosing the right rollback — with the instrumentation that actually helped on my Rork apps.
Building a Breathing-Paced Haptic for a Meditation App with CoreHaptics
Canned expo-haptics buzzes can't produce the swell of a breath. Here is how to call CoreHaptics continuous events and parameter curves from an Expo native module to build a haptic synced to 4-7-8 breathing, with working Swift and TypeScript code.
The Post You Wrote Offline Shows Up Twice — Designing a Send Outbox That Survives Retries
Persisting a queue and replaying it isn't enough — a lost response turns into a duplicate write. Here's a send outbox with idempotency keys, temp-to-server ID remapping, and poison-message quarantine, in working TypeScript.
What Your App Should Do When Someone Turns On Reduce Motion — A Motion-Respecting Layer in Expo
When a user enables iOS Reduce Motion or Android Remove Animations, how should your app respond? Combine AccessibilityInfo with Reanimated's ReduceMotion to replace heavy motion with a calmer alternative instead of simply switching it off.
Why Your Prices Show as “¥1234” on Some Phones — A Formatting Layer That Doesn't Trust Intl Alone in Expo
Same code, yet one device shows “¥1,480” and another “¥1480.” In Expo / Hermes, Intl leans on each device's locale data, so output can drift by OS and engine. Here is a resilient formatting layer that centralizes currency, number, date, and timezone handling and falls back gracefully where Intl is incomplete — with working code.
The Private Screen That Lingers in the App Switcher — Hiding the Snapshot iOS Takes the Moment You Background Your App
When you send a React Native app generated by Rork to the background, iOS photographs the current screen for the App Switcher and writes it to disk. Journals and personal input screens linger there in plain sight. This walks through the iOS privacy overlay (why inactive, not background), Android's FLAG_SECURE, scoping it to sensitive screens only, and screenshot detection — all in working code.
When a Poisoned Cache Crashes Your App on Every Launch — Designing a Safe-Mode Boot Your Users Can Escape On Their Own
When a persisted cache goes bad and the app crashes at the same spot on every launch, the only option left to the user is to reinstall. This article designs a safe-mode boot for Expo (React Native): the app counts its own early crashes, confirms a launch only once it becomes interactive, and resets just the dangerous state in graduated steps.
Build a Toast System in Your Rork App That Survives Overlaps, Screen Readers, and Notches
When you add toast notifications to a React Native app generated by Rork, the naive version breaks in three places: two toasts overlap, screen readers stay silent, and the text hides under the notch or home indicator. This walks through a root-level queue, animations decoupled from your app tree, AccessibilityInfo announcements, and safe-area placement — all in working code.
Hardcoding Your OpenAI Key in a Rork (Expo) App Means It Gets Stolen — Slip a Thin Worker Proxy In Between
Embed an OpenAI or Gemini API key directly in the Expo app Rork generates and it can be extracted from the shipped binary. Here is why a key inside an app is never secret, plus a minimal Cloudflare Workers proxy that hides it (streaming passthrough included), simple abuse controls, and key rotation that needs no app review.
Your Rork App's Photos Look Sideways Only After Upload — Normalizing EXIF Orientation and Stripping Location Metadata
A photo that looks upright in your app rotates 90 degrees once it hits your server. The cause is the EXIF Orientation tag. Here's how to bake the rotation into pixels and strip location metadata with expo-image-manipulator before uploading.
Your List Jumps Back to the Top — Restoring Scroll Position Across Back Navigation and Process Death
How I rebuilt scroll restoration for a wallpaper grid by splitting it into two unrelated problems — back navigation and process death — covering getItemLayout, save timing, and killing the restore flicker.