OCAT is described as 'Open Capture and Analytics Tool. If you want to know how well a game is performing on your machine in real-time with low overhead. It supports all major APIs on Windows – Direct3D® 11, 12 and Vulkan® – and can show an in-game overlay'. There are more than 25 alternatives to OCAT for a variety of platforms, including Windows, Mac, Linux, Android and iPhone. The best alternative is Open Hardware Monitor, which is both free and Open Source. Other great apps like OCAT are MSI Afterburner (Free), iStat Menus (Paid), 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.
iStat is a series of system monitor apps. It's available in different versions: iStat Menus, iStat for iOS and iStat Server as a companion application to the iStat for iOS app that lets you remotely monitor your computers (free for Windows and Mac).
FPS Monitor tracks your PC's hardware state and displays this information as an overlay in-game. You no longer need to switch to desktop or attach a second display to control your hardware status. FPS Monitor will show all valuable information in-game.
Nvidia Inspector is a small and handy tool that displays hardware information for Nvidia-based graphic cards. Main features also include: hardware monitoring, Core/Shader/Memory clock tuning, Fan Speed adjustment, etc.