Creating icons
The icons in this demo all use real icns files converted to png. These have padding included to account for the shadows.
To create your own in a consistent style, start with a 512px outer frame with 50px padding. The inner frame will be your app and should have 92px radius, with 60% smoothing (you'll need Figma for this).
Find the template below.
Finding icns files on your Mac
Find the app inside the Applications folder, right-click and select "Show Package Contents".
You'll find all the icns files in Contents/Resources. These will need to be converted to png via the free tool below.