Afloat is a free, no longer developed app that adds many window management features to most Mac applications.
Once installed, look in the Window menu of your favorite application, and you will find Float's commands there â€“ they have a cloud badge before their title. If you don't find them, it's likely Float doesn't work with that application. Carbon applications like the Finder and iTunes won't work, but Cocoa apps like Safari and iChat will.)
Keep Afloat: Keep windows afloat on top of all others.
Transparency: Lets you see through a window.
Drag Anywhere: Let's you move a window by â€œgrabbingâ€ it from anywhere (not necessarily the title bar).
Resize Anywhere: Lets you resize a window by â€œgrabbingâ€ it from any point (not just the bottom-right corner).
On All Spaces: Makes a window remain on the screen even if you switch Spaces.
Overlay: Makes a window floating and transparent and makes it ignore your mouse clicks (they â€œfall throughâ€ to the windows below it instead).
Show Windowâ€™s File in Finder: If a window represents an open file, it will show the file in Finder (it's got a keyboard shortcut for you keyboard addicts).
Pin to Desktop and more: Look in the Adjust Effects pane of your window for more.