Top rated in System Optimization

SecondBar
1.1
FREE
SecondBar creates a copy of your Menu Bar for your second display.
MacClean
3.5
Remove unneeded junk data and protect your privacy.
DiskTools Pro
3.8.3
DiskTools Pro makes Mac repair and maintenance painless, fast and easy.
xScope
4.3.1
A tool for measuring and inspecting on-screen graphics.
MUMenu
2.1.4
FREE
Menubar item application that will check for software updates.
gfxCardStatus
2.4.4
Free menu bar application that keeps track of which graphics card your MacBook Pro is using at any given time....
Memory Cleaner
5.1
The first Memory Cleaner on the Mac App Store!
Lion Cache Cleaner
7.0.9
System maintenance application.
Mountain Tweaks
1.1
FREE
Brand new tweaking tool to deal with the annoying changes in OS X 10.8 -- with just a click of a button....
MemoryKeeper
1.3
FREE
This program helps you optimize your Mac's memory.
AVG Cleaner
2015.0.4766
FREE
This program helps you clean unnecessary clutter from your Mac.
Memory Diag
1.2
FREE
This program helps you optimize memory usage on your Mac.
Yasu
5.0
FREE
Yasu was originally created with System Administrators who service large groups of workstations in mind......
Pref Setter
2.0
FREE
A simple solution that allows users to edit plist files on their Mac.
Nocturne
2.0
FREE
Change the color scheme of your display with just a few clicks.
What's Keeping Me?
2.4
FREE
App that identifies what is keeping you from emptying Trash.
MarcoPolo
2.5.1
FREE
MarcoPolo brings context-aware computing to your portable Mac computer.
QuicKeys
4.0.7
QuicKeys dramatically reduces time and effort spent on your Mac by automating all your most routinely-performed......
TrashMe
2.1.21
IMPORTANT Before posting review saying TrashMe can't uninstall main app...
LoadInDock
1.1.1
Tiny application which shows the CPU load in the Dock.
MiniUsage
3.0.1
FREE
This app monitors CPU usage, battery status, and many others.
System Toolkit
2.0.10
Information and maintenance app designed for macOS.
MrClean
1.8
FREE
A powerful application that makes you able to clean your Mac.
App Tamer
2.4.7
Slow down or pause your apps when you're not using them.
App Cleaner
6.7.1
Completely remove utilities from your Mac computer.