App Icon Generator

App Icon Generator

Generate an app icon programmatically with a CoreGraphics Swift script, resize it to every required size, and install it into the Xcode asset catalog — with appearance variants (light/dark/tinted).

Read first — the Liquid Glass era (iOS 26 / macOS 26)

Apple icon standards verified as of July 2026 — Icon Composer, Xcode 26, macOS Tahoe 26.4+. This guidance is static (the skill does no per-run web lookup); if that date is well in the past or the OS has moved on, re-verify against the HIG · App icons before trusting the specifics below.

Apple's shippable icon format changed. On iOS 26 / macOS 26 the modern app icon is a layered, light-responsive Liquid Glass icon authored in Icon Composer (free; ships with Xcode 26, needs macOS Tahoe 26.4+). You supply flat artwork in up to four depth groups (background → foreground); the system renders the glass — specular highlights, refraction, translucency, shadows — and masks the rounded-rect shape. One .icon file adapts across iPhone, iPad, Mac, and Apple Watch and across Default / Dark / Mono (tinted) appearances.

So this skill does NOT produce the final iOS 26 icon. Icon Composer is GUI-first; no script can author a true layered .icon. Its two honest roles are:

1. Placeholder — a fast flat 1024 PNG so early builds, TestFlight, and screenshots feel real before you invest in the real icon.
2. Layered source art — flat background / midground / foreground PNGs (or SVGs), effect-free, ready to drag into Icon Composer, where you assemble depth and export the .icon.

What changed vs. the classic flow:

• Do not bake in lighting. No pre-painted specular highlights, drop shadows, or gradients-used-as-lighting — the system owns those now, and baking them in double-exposes against the system glass. (The drawShine/drawShadow blocks below are legacy-only, off by default for iOS 26+ targets.)
• Do not round the corners. Icon Composer / the system apply the shape mask — fill a full square canvas.
• SVG for shapes, PNG for effects — vector where you can, raster only where you must.
• Provide appearance variants — light (default), dark, and tinted/mono. A single flat PNG only fills the light slot and won't adapt on iOS 18+.

Detect the target first: read the deployment target (IPHONEOS_DEPLOYMENT_TARGET / MACOSX_DEPLOYMENT_TARGET in the pbxproj, or .planning/APP.md). iOS 26+ / macOS 26+ → lead with the Icon Composer handoff and treat the flat PNG as a placeholder. Older targets → the classic flat + appearances path is fine to ship. If the deployment target is newer than the "verified as of" date above, flag it to the user and re-verify the icon rules against the current HIG before generating — the skill won't know about anything Apple shipped after that date.

When This Skill Activates

Use this skill when the user:

• Asks to "generate an app icon" or "create an icon"
• Wants a "placeholder icon" or "app icon design"
• Mentions "icon for my app" or "need an app icon"
• Asks to "update the app icon"

Pre-Generation Checks

1. Project Context Detection

Glob: **/Assets.xcassets/AppIcon.appiconset/Contents.json

• Identify platform: macOS, iOS, or universal