About
SketchScreen is the fastest way to draw on your screen - no app switching, no setup, just press a hotkey and start annotating.
Freehand, arrows, shapes, text, laser pointer. Works on Windows, macOS, and Linux.
One tool. Every platform. One-time payment.
Also — the current description in the screenshot says "Works on Windows and macOS" — you should update that to include Linux since that's your moat.