Kacha
Screenshot tool for Linux, macOS and Windows: capture, annotate and copy to the clipboard.

About
A screenshot tool for Linux, macOS and Windows, written in Go and drawn with MyGo's native UI. You frame a window on screen, annotate the capture and copy it to the clipboard. On Linux it relies on xdg-desktop-portal and wl-clipboard; the name comes from the sound of a camera shutter, kacha.