ksnip

A Qt-based screenshot tool that works the same way on all three operating systems: rectangular area, last area, full screen, active window or the window under the cursor. After capturing you add arrows, shapes, text, numbered stickers, blur or pixelation of sensitive data, and save as an image or PDF. It suits documenting a bug in engineering software, marking up a drawing or a chart, and preparing an internal guide with annotated captures. It can also capture from the command line. Limitation: some capture modes are restricted on Wayland and macOS.