Part 3 — Custom themes, multi-window, and polish
Level: Advanced · Time: ~60 minutes · Builds on: Part 2 — Search, palette, and settings
The gap between "a nice SwiftUI project" and "an app that feels professional" lives entirely in the details you skip when you're moving fast: brand-owned theming, real multi-window support on macOS, business-rule validation, tabular data that scales, and the ambient polish (alerts, popovers, tooltips, accessibility) that users notice only when it's missing. This tutorial closes every one of those gaps.
By the end you'll have a Contacts app that could stand next to a paid product without embarrassment — and the muscle memory to know exactly which corners are worth cutting on the next one.
What we're adding
