I'm an avid user of system applications. I like to know what's going on my system. Which is why I'm using a lot of Windows Sysinternals utilities like AutoRuns, Process Monitor, Process Explorer. To some extend also some of NirSoft's Utilities.
Well, recently I stumbled upon what you may call an "application center", KLS Soft's WSCC aka Windows System Control Center.
Essentially, WSCC provides a convenient GUI and lists all of Sysinternals', NirSoft's and Window's own utilities in a comfortable order. There are 2 ways to run WSCC, though.
You can choose not to download every application which results in longer starting times of each application. Because every time you start WSCC the application needs to be downloaded and cached. The cache is emptied upon closing WSCC and you have to re-download said application upon starting WSCC again.
Or you can choose to download every one of the applications via "Updates" in the upper right corner in a chosen folder resulting in shorter starting times.
WSCC is a must-have for everybody who likes to know what's going on with their system! The sheer amount of utilities should satisfy almost any need!