To make menu bar app screenshots for the Mac App Store, you need to fill 2800 by 1880 pixels with something that highlights a widget in the corner of the screen.
Geoff Hackworth did this:
- Take retina screenshot of the app in action (he used Sidecar on his iPad to get his non-retina Mac to produce a large picture).
- Prepare a 2880x1800px canvas with a MacBook bezel template, put the screenshot inside.
- Center the picture so the icon and the menu bar popup window takes center stage.
- Put marketing text around that.
Since today, you can look at the result of this on the App Store: check out Geoff’s app “SF Menu Bar”.