Firefoxy is an app that applies Philippe Wittenberg's fancy Firefox widgets via drag-and-drop. Just drag Firefox onto Firefoxy, and it will do its thing. Drag it on a second time to revert to the default widgets. Or just open the app and it will prompt you to locate Firefox.
What this app does: This app places a couple files inside the Firefox application that tell Firefox how to draw the widgets that you find on websites. These include text buttons ("Submit," "Cancel," etc.), text input fields, radio buttons, checkboxes, pull-down lists, etc. After using Firefoxy, your widgets should look like those in the image below.