SnapRuler - on-screen ruler for Mac which snaps to the shapes you measure

We wanted to make Snap Ruler as smooth and light as possible. We didn’t want to suffer from the first GitHub for Mac problem - gorgeous, but mainly unusable.

Snapping to objects is quite computationally-heavy, especially detecting rounded corners and such. Therefore we make all the heavy-lifting on the GPU.

Making the animations smooth, even on the older machines (like the 1st gen MacBook Air), was possible by carefully setting the Blending mode and buffering every CoreAnimation layer that we could.

But, to be honest, most performance gain comes from not redrawing anything until absolutely necessary.

Development and design took 1.5 months, with just the two of us: me (design, UX, UI, features, hallway testing, keeping it all together) and my fellow co-founder Tomek (Cocoa magic).