skip-app-design

Building SwiftUI views in Skip projects that work on both iOS and Android. Covers supported components, navigation, state management, Jetpack Compose customization, Material 3 theming, the hard rule against `Image(systemName:)` / `Label(_, systemImage:)` (use `.symbolset` resources via `Image("name", bundle: .module)` instead), and the localization-correct `Label { Text } icon: { Image }` shape.

Start-to-finish orchestrator for building a new cross-platform Skip app. Sequences the other Skip skills in the order you actually need them — scaffold with `skip init`, write SwiftUI, add Material Symbols icons, validate Kotlin transpilation with `swift test`, drive the running app with `skip app launch` + Maestro, localise via `Localizable.xcstrings`, and ship via `skip export` with fastlane metadata. Use this skill at the start of a new project, or when picking up an existing Skip app and trying to decide which skill applies to which phase. Each phase links to the dedicated skill for the deep dive. Also points at the `skipapp-todo` working example at https://github.com/skiptools/skills as a reference build.

Integrating optional Skip frameworks into a project. Covers Firebase, SQLite, Keychain, WebView, audio/video, device sensors, Lottie animations, FFI, and other frameworks. Includes Package.swift dependencies, skip.yml configuration, and usage examples.

Building Skip apps in Fuse mode — Swift compiled natively for Android via the Swift Android SDK (Swift 6.3+), with auto-generated JNI bridging between Swift and Kotlin/Java. Covers when to choose Fuse over Lite, project init with `skip init --native-app`, the `mode: 'native'` + `bridging: true` skip.yml configuration, the `import SkipFuse` requirement for `@Observable` models (a build-time warning, not an error), the internal/public visibility rules for views and properties, the ~60 MB Swift runtime binary cost, debugging via `OSLog.Logger` (breakpoints not yet supported), `ProcessInfo.processInfo.dynamicAndroidContext()` for reaching the Android Context, the Kotlin-inline-class string-interpolation workaround for Android SDK properties, `SKIP_BRIDGE=1` for dynamic library bundling, and the `skip android test` (CLI vs APK mode) test command. Use this skill whenever working on a project whose `skip.yml` contains `mode: 'native'`, or when deciding between Lite and Fuse for a new app.

Icons in Skip projects. The hard rule: never use `Image(systemName:)` or `Label(_, systemImage:)`. SF Symbols are an Apple-only catalogue with no Android equivalent; the names you pass to `systemName:` / `systemImage:` will not resolve on Android and most will render as a blank or generic-placeholder glyph. The canonical replacement is to download Material Symbols from `fonts.google.com/icons` in **Apple symbolset format**, drop the `.symbolset/` bundle under `Sources/<Module>/Resources/Icons.xcassets/`, and render with `Image("name", bundle: .module)` inside the localisation-correct `Label { Text(…, bundle: .module) } icon: { Image(…) }` form. The same SVG ships to both platforms and looks identical. Also covers app launcher icons via `skip icon` and how to verify in-app icons render on both platforms. The full `.symbolset` format spec (download URLs per variant, `Contents.json` schemas, verification checks) is in references/symbolset-anatomy.md. references/sf-symbol-map.md explains what SkipUI does with `systemName:` internally — it is **not** a "safe-to-use" list. Use this skill whenever adding, replacing, or auditing icons in a Skip app or library.