This will be TechSmith's loss. I'm tried of the Windows propaganda, so I'm switching to Ubuntu with LibreOffice. I guess I'll figure out some other capture application.
What functionality are you trying to match on Linux?
ffmpeg and OBS are excellent free video recorders on Linux and maim (https://github.com/naelstrof/maim) is a fantastic way to capture screenshots. You can easily pick 1 screen, multiple screens, a specific window or mouse drag a custom rect -- all bound by custom hotkeys.
