Toolabs DSM - Design System Manager plugin for creating themeable designs
xScope - xScope is an excellent utility that is used to measure the graphic layouts or any application’s dimensions for checking the operating systems’ compatibility with the desktop screen.
Evie by unDraw - MIT licensed illustrations for your next project
PixelSnap - Measure every pixel on your screen with ease ✨
Haiku - Haiku is an open source OS catered specifically to the needs of personal computing.
QuickLens - Inspect the UI of apps, illustrations & websites like a pro