Fade In
Having used Final Draft screenwriting software for years, I just rewrote a film script for a screenwriting client using Fade In (https://www.fadeinpro.com) I like it. I think Fade In offers more than a viable alternative to Final Draft. I think it’s better in some respects. At $79.95 for the pro version (recommended) it’s certainly a lot cheaper. You can use the demo version quite well enough to write a screenplay with no lose of functionality. Worth giving it a shot if your budget doesn’t stretch to Final Draft, or if you just want to use an excellent, free screenwriting software tool, which is what the demo version is. I recommend upgrading to pro if you can.
Happy screenwriting.