App icon
The home-screen tile that carries your whole brand at thumbnail size, under strict platform rules about shape, transparency, and safe area.
See it
What it is
The app icon is your entire brand compressed into roughly 60 points (logical pixels) on the home screen, drawn at two or three times that in real device pixels, sitting next to Instagram and a bank app. It is designed at 1024x1024 and judged at thumbnail size, which is why the icons that work are one bold shape, two or three colors, and heavy contrast against both light and dark wallpapers. Wordmarks, thin strokes, and screenshots of your UI all dissolve.
Platform mechanics differ and both bite. iOS wants a full-bleed square with no transparency and no alpha channel (a PNG with alpha is a common upload rejection), applies its own rounded mask, and since iOS 18 also renders dark and tinted variants you should supply rather than let the system guess. Android adaptive icons split into a foreground and background layer on a 108dp canvas where the only region guaranteed to survive is a centered circle 66dp across, not a 66dp square, because launchers mask the artwork into circles, squircles, and teardrops; art that spills outside that circle gets its corners shaved.
Practical notes: never bake your own rounded corners or drop shadow, the OS adds them and you end up with corners inside corners. Test at actual size on a real device before you commit, and remember the icon is also the store listing's first impression, where it sits beside competitor icons in search results.
Ask AI for it
Design an app icon for [app name], which does [purpose, one sentence]. Brand colors: [hex values]. Symbol direction: [the object, letterform, or abstract shape you want, or 'propose three options']. References attached: [logo files, existing marks, icons whose feel I like]. Rules: one bold central mark, no text, no thin strokes, at most three colors, and enough contrast to read on both light and dark wallpapers. Deliver a 1024x1024 full-bleed PNG with no transparency, no pre-applied rounded corners, and no drop shadow, plus an Android adaptive version split into foreground and background layers with all key artwork inside the centered 66dp-diameter safe circle of the 108dp canvas. Show it previewed at 60 points on both a light and a dark background to confirm it still reads.