StoreKit 2, Part 3: Server-Side Receipt Validation in 2026 (App Store Server API)
Day 17 of the 30-day iOS series, the finale of three on monetization. You can't trust the client — here's the minimal App Store Server API workflow for BrewLog: Server Notifications V2, JWSTransaction decoding, a Cloudflare Worker, and three pure Swift tests that prove the entitlement logic without ever calling Apple.
StoreKit 2, Part 2: Free Trials, Win-Back Offers, and Promo Codes That Actually Convert
Day 16 of the 30-day iOS series. I add a 7-day free trial, a win-back banner for lapsed subscribers, and offer-code redemption to BrewLog's paywall — concrete App Store Connect configuration plus the Swift code, all covered by Swift Testing.
A StoreKit 2 Paywall From Scratch: Subscriptions, a Transaction Listener, and a Restore Button That Works
Day 15 of the 30-day iOS series, first of a three-part run on monetization. I built BrewLog's real paywall with StoreKit 2 — two subscription products, a transaction listener, and a restore flow — with zero third-party SDKs. Every number the paywall shows comes from one pure, tested function.
SwiftData Two Years Later: What's Solid, What Still Bites, and the Migration Test You're Not Writing
Day 14 of the 30-day iOS series. SwiftData is about two years old now, and the honest verdict is mixed. I already wrote the long field report on where it broke in production — this post is the part that report didn't have room for: a VersionedSchema + SchemaMigrationPlan test that proves a schema change is safe BEFORE TestFlight finds out for you.
@Observable vs ObservableObject: What 1,000 Rows and a Redraw Counter Actually Showed Me
Day 13 of the 30-day iOS series. I built a redraw counter into BrewLog, put 1,000 rows in two identical lists side by side — one backed by @Observable, one by ObservableObject — and toggled a single favorite ten times. The row counts tied 10-10. The list counts didn't. Here's the real number, and exactly where it comes from.
@State, @Bindable, @Environment: The Complete Map for @Observable (and the Question You're Actually Asking)
Day 12 of the 30-day iOS series. With @Observable, SwiftUI lets you slap @State, @Bindable, @Environment, or a plain let on the same class — and compiles all of them. Here's the question that actually decides which one is correct, one map that resolves 95% of the confusion, and three real BrewLog bugs (one silent, one a compile error, one a runtime crash) that come from picking wrong.
ObservableObject → @Observable: The Migration Guide That Skips the Marketing (and the Autoclosure Gotcha Apple Forgot to Mention)
Day 11 of the 30-day iOS series. Apple's migration guide makes ObservableObject → @Observable look like a find-and-replace. It mostly is — except for one quiet behavioral change: @StateObject only ran your initializer once, and @State runs it on every render. Here's the multiple-init bug that causes, why it's worst in exactly the init you were proud of, and how to fix it with a test that turns 'no side effects in init' into a hard, green invariant.
ThinkBud + Foundation Models: What I Shipped On-Device, and the Wall That Sent Me Back to the Server
Day 10 of the 30-day iOS series, the build-in-public finale of AI week. I took the on-device Foundation Models stack from Days 8 and 9 and bolted it into ThinkBud, an app I actually ship. Here's the honest field report: the bounded tasks the on-device model nailed for free and offline, the context-window wall a 100K-character textbook import smashed into, and the exact line of code where I gave up and routed to a server. Plus the one decision that's pure Swift — so it gets a real test.
@Generable: Make Apple's On-Device Model Hand You a Swift Struct, Not a String to Parse
Day 9 of the 30-day iOS series, part 2 of AI week. Yesterday Foundation Models gave us a String. Today we make it give us a typed Swift value — BrewSummary(flavor:, advice:, rating:) instead of a paragraph you regex your way through. @Generable, @Guide constraints, session.respond(to:generating:), and the sleeper-within-the-sleeper: tool calling, where the on-device model calls your own Swift code mid-answer. With the TDD seam, because typed output changes what you test.
Foundation Models: Your First On-Device AI Feature With No Backend, No API Key, No Bill
Day 8 of the 30-day iOS series, and the start of AI week. The Foundation Models framework runs a real language model entirely on the phone — free, private, offline. We build the smallest thing that works: summarize a block of text in three lines, handle the availability cases that bite in production, wire it into a real app, and put a TDD seam around the part that isn't the model. Code-along, with tests.
UIDesignRequiresCompatibility: When (and Why) Opting Out of Liquid Glass Is the Pro Move
Apple hands you one Info.plist key that freezes the old design for a full year. It's not a cop-out — for banking, enterprise, and apps caught mid-redesign, opting out of Liquid Glass is the responsible call. The exact flag, a real before/after from my own app, the deadline, and a decision matrix you can actually defend in a standup. Plus the per-screen rollout gate you should be testing instead.
Icon Composer and the New App-Icon Era: One Document Instead of Three Exported PNGs
iOS 26 wants your app icon in light, dark, clear, and tinted. The old way was three flat 1024px PNGs that quietly drifted apart. Icon Composer turns it into one layered .icon document the system relights for you. The real workflow from a single SVG to a full set — plus the one decision around icons you can actually unit-test.
Custom Liquid Glass Components: When to Leave the Defaults (and the Three Mistakes That Kill Your Frame Rate)
glassEffect(.regular, in:) with a custom shape, two glass blobs that morph into each other with glassEffectID, and the three things that turn buttery Liquid Glass into a stutter machine. Built on a real iPhone 17 Pro simulator, with the TDD seam that keeps the decision testable even though the render isn't.
Liquid Glass for an App You Already Shipped: What You Get From a Recompile vs. Five Lines of Tuning
I rebuilt a real SwiftUI app against the iOS 26 SDK and took two screenshots of the exact same screen — one with zero code changes, one with five lines of glassEffect. Here's the honest split between what the recompile hands you for free and what's worth your custom-tuning time, plus the TDD seam that makes a visual feature testable.
What iOS Dev Land Is Missing in 2026 — and a Few Things I Built to Fill the Gaps
There are a handful of small, specific frictions every iOS developer hits this year that should not still exist in 2026 — Privacy Manifests, Universal Links validation, iOS 26 icon variants, App Store screenshots. Walking through what's actually missing, why it persists, and four free tools I made for myself that you might find useful too.
We Updated Our App Icon for iOS 26. Apple Now Wants Three of Them. So We Built a Tool.
iOS 26 Liquid Glass quietly tripled the work to ship an app icon — default, tinted, and dark variants for every iPhone app. Existing icon tools haven't caught up. We hit the wall updating ThinkBud last week, so we built a free generator. Here's what changed in iOS 26, why every iOS dev is about to learn this the hard way, and the tool we shipped to handle it.