McKinley: The SF Symbols Editor Apple Never Built

The Apple-created graphics that appear on your folders are called SF Symbols. There are thousands of them, and they're designed to stay legible in multiple sizes and weights, from tiny up to headline-sized. Apple allows you to create your own, in a process that turns out to be pretty complicated when done correctly. You're drawing potentially nine weights (Ultralight through Black) at three scales, making sure the strokes stay visually consistent at every combination, making sure the whole thing still reads as the same symbol from thin to bold, and doing it all in a way Xcode will accept without silently failing. Most people who've tried this by hand in Illustrator or Sketch will tell you it's tedious, error-prone, and genuinely difficult to keep consistent.

McKinley is a dedicated app built to solve exactly that problem. It's a vector drawing tool, but unlike a general-purpose one, it already understands the SF Symbols format: the weight system, the scale system, the export rules Xcode expects. You draw a shape once, and McKinley handles generating and keeping consistent the different weights and sizes that shape needs to become a real, working custom symbol, rather than you manually redrawing (and re-aligning) it nine times. It can start from an SVG you already have or from a blank canvas, it live-previews your symbol using Apple's actual rendering engine, so what you see is what will really show up in an app, and when you're done it exports straight into a format Xcode can use. It launched September 7, 2026, runs on macOS 15 and up, and it's made by one developer, Amy Worrall, under the name Double & Thrice Ltd.

I don't have many developer chops, so this isn't going to end up in my daily driver stack, but I was intrigued because John Gruber, from Daring Fireball, raved about McKinley as "a remarkable 1.0." Double & Thrice provided me with a reviewer's license, and I installed and tested it.

Several things were impressive. The documentation, including a list of the app's limitations, is well done. When the app encounters an issue, the error messages are descriptive and helpful. To my eyes, the symbols it creates are indistinguishable from the ones in Apple's built-in set.

The kicker is the pricing. Gruber called McKinley a serious professional tool for dev shops and graphics pros. £55 / €65 / $60, one-time. There's a 15% launch discount (down to roughly £46.75 / €55.25 / $51) through September 14, 2026, and a free 14-day trial that's described as fully functional, not a crippled demo. For a solo-developer niche tool, that's a reasonable way to let it prove itself before you pay.

Normally, I list alternatives to apps when I review them, but there doesn't seem to be anyone else making anything that does what McKinley does. That kind of original thinking is rare, so hats off to the dev.