Here are some tools (apps and online) that will help you get your TV or movie script in shape. There are more writing tools at the tech tools site. If you have other suggestions, feel free to send them my way.
Script-writing software with similar features toFinal Draft without the price tag. Not as many of the extras that come withFinal Draft but only $50. Windows, Mac, Linux.
Industry standard for writing screenplays on both Windows and Mac. Notes section for keeping track of characters, special scene view to get an overview, index card system for summaries, etc. $170.