Google Input Tools for Windows
Free Online Software to Write in Various Languages
This small tool doesn't require any installation and given its tiny size, it hardly uses system resources, so you may leave it working in the background. As CPU and RAM usage varies, you'll notice color changes which makes the information easier to track.
While this may be enough for users who just want to have a look at CPU and RAM resources from time to time, it falls too short of other similar applications that offer more system data and a wider selection of elements to control.