Please never change the simplicity of your program!
I love that it has just four buttons: dark/light mode, download *.txt, eraser and full screen. Your piece of software made me instantly concentrate with laser sharp focus. Usually, I'm quite overwhelmed by my writing and the more I write, the more annoyed I get. So much to edit. Blah. The app achieves exactly what you've promised!
As a sidenote, something beautiful happened, I started playing around with long and short sentences. I even found some of my sentences beautiful. Something that had never happened before because I was constantly overwhelmed by all the other stuff, paragraphing, coherence and whatnot.
I was a bit irritated first that the program allowed me to erase multiple lines (it violates a bit the no-editing mindset) but later I found this option quite helpful when I needed to change the beginning of a sentence to steer in another direction that flowed better.
What I would love the program to have is, from the perspective of a writer, to know that the text I've written is somewhere safely stored on my computer like a backup file or something. That way, I wouldn't need to worry about the system breaking down and me losing all my work. For a serious writer, knowing that the text is securely stored somewhere in a backup file and readable with any program, would erase the fear and enhance the flow of writing. Furthermore, at first, I wondered if there is a limit of how many words I can write before the software breaks down or tells me I reached the maximum capacity. I think I'm allowed to write as much as I want, 100.000 words or 1.000.000 words, right? However, it would be super nice if you would communicate that.
Even though I love the word count because it gives me a sense of space and time, I would like to be able to turn it off, so I can enter a true flow state. Forgetting about space, time, and word count. https://endel.io/ for example uses infinite soundscapes to create flow states. That way, the human mind doesn't get jolted out of the experience, the science says. Maybe the same approached could be applied to your program, too? Anything that gives you a sense of time and space should be avoided to enable the writer to be fully immersed in writing. Because every so often I looked at the bottom right of the screen and saw that I've written 1000 words and started to wonder if I've already written enough, but in reality, I shouldn't have to worry about those kinds of things. I should just write.
I am, will do!
What features does the web app miss?