Winston is described as 'is the typewriter simulator for macOS. Perfect for one thing: Writing. Just writing. Without losing focus of your ideas, without the constant backtracking and endless fussing over your text, judging it too soon and killing your ideas dead!' and is an app in the News & Books category. There are three alternatives to Winston for Online / Web-based and Windows. The best alternative is AHOY!, which is free. Other great apps like Winston are Typewrite Something (Free) and OverType (Free).
OverType is the over-the-top typewriter simulator. It's a straightforward, easy-to-use web app featuring several fonts reminiscent of real typewriters and adjustable sliders for Brokenness and Ribbon Ink.