PiP for Mac - Always on top window preview similar to the popular windows only OnTopReplica
DaisyDisk - DaisyDisk is a disk analyzer tool for OS X that visualizes hard disk usage and allows to free up hard disk space.
Helium - Helium lets you accept payments by credit card for anything you want to sell online.
CleanMyMac X - Clean, protect and speed up your Mac
X-Mouse Button Control - XMouse Button Control (XMBC) allows you to create application and window specific profiles.
MacFly Pro - Smart assistant for better Mac performance