This is a super interesting idea. I work with a lot of undergraduate students who struggle with the writing/editing divide, and I will absolutely be recommending that they try this tool.
I've never done anything resembling professional writing, but I've always found myself creatively paralyzed when sitting in front of a keyboard. Not quite sure why, but it's so much easier to let it all flow out with a pencil and paper.
That can definitely help! I do work with some students who have learning challenges or other issues with writing, physical or otherwise, for whom writing by hand isn't an option. Freewriting is a good idea whether by pencil or by keyboard, though!
Hey, OP here. Glad you liked Earnest, I wrote it for myself a while back and have been using it for almost all my writing, does make a hell of a difference for me - seeing as I found it so useful I decided to tidy it up and release it.