PiP for Mac - Always on top window preview similar to the popular windows only OnTopReplica
KiCad - A Cross Platform and Open Source Electronics Design Automation Suite
Helium - Helium lets you accept payments by credit card for anything you want to sell online.
Proteus PCB design - Proteus PCB design combines the schematic capture and ARES PCB layout programs to provide a...
X-Mouse Button Control - XMouse Button Control (XMBC) allows you to create application and window specific profiles.
Altium Designer - PCB Design Software