GOverlay is described as 'opensource project that aims to create a Graphical UI to help manage Linux overlays' and is a System Information Utility in the System & Hardware category. There are seven alternatives to GOverlay for Mac, Windows, Linux, Mono and Proton. The best alternative is Open Hardware Monitor, which is both free and Open Source. Other great apps like GOverlay are MSI Afterburner (Free), MangoHUD (Free, Open Source), Stats (Free, Open Source) and RivaTuner (Free).
A powerful overclocking tool for your graphics card, which also includes screen capture and video capture tools, plus overlays. Has a lower FPS hit than Fraps, and offers the same functionality. The beta versions include audio streams alongside the video capture.