Align windows in osx
http://www.irradiatedsoftware.com/twoup/
while it doesn’t do cascade of windows, it does a lot for being free. It can send a window to the left/right/top/bottom half of a window. The full paid version allows a little more. Seems to work fine, after I reset the hotkeys.
Useful when trying to view two windows/apps at the same time.