I have really missed graphs of system status from android. I wanted something like you have in task manager on windows, or widgets on my KDE desktop. When I found nothing like that, I decided to write one, here it is.

Usemon is a simple application for monitoring usage of system resources. It displays graphs of CPU, RAM, and network usage. No root needed. It is extremely lightweight, because it gets these data directly from the kernel. It can show statusbar notifications of these too.