I use CCleaner on my Windows systems. I does not run as a service. Since it does not run as a service it does not regularly display notices on my desktop telling me I need to use. So why does every single android app that does something similar, and almost every other app I try to install, want to run in the background and send me notices? This is the same reason I banned Adobe Reader from my desktops.
Please Android developers, stop acting like your app is so important that it need to be constantly running and eating up my resources.