Some how or other I stumbled across Trelby and so far I really like it. It's the first screenwriting app I've come across that is both intuitive and stable. I have tried every screenwriting application, free and commercial, that's available (most more then once) and I've had trouble with all of them except Movie Draft, which is still too "young", and now Trelby. (I like Scrivener too as a writing tool but it's only does screenwriting as a "hobby".)
I kinda like Final Draft, but
Granted, like all OS projects, Trelby is lacking a few things, but I was able to start working right away without being frustrated by bizzare menus and non-intuitive commands. And didn't crash in the first few minutes. And I didn't have to pay $250 for it.
Most apps are Mac ports, and they just don't do a good job of working the way Windows users work. I've been working with computers and writing software for about 25 years. Certain command/key-strokes are encoded in my DNA. I can just suddenly start using Ctrl-4 when I want to do a search. And I shouldn't have too. I want the tool to get out of my way so I can write my story. I don't want to have to rethink how to use my computer.
So far, Trelby seems to be doing that for me. Thanks.