I think Hemingway mode is when backspace and delete are disabled. Ghostwriter (https://wereturtle.github.io/ghostwriter/ https://wereturtle.github.io/ghostwrite

I think Hemingway mode is when backspace and delete are disabled. Ghostwriter (https://wereturtle.github.io/ghostwriter/ https://wereturtle.github.io/ghostwriter/) has Hemingway mode and another mode that they call "distraction free mode" which highlights just the current sentence. FWIW I find it really distracting to have the current sentence highlighted because it means the file's appearance changes more than it otherwise would. Sublime Text has a "distraction free mode" (shift+F11) which goes to fullscreen, hides all menus, limits the current file width, and centers the file's contents.