The amazing Dean Stokes came up with a great solution in this blog post, but many of the schools that I work with wanted something that simply existed on the device that could be printed immediately. There are a few Chrome App notepads that have offline editing mode, but a lot required a sign in and none seemed fully fit for purpose.
I then remembered, that you can launch a simple, editable html file with a URL. No need for a web connection. No sign in. Simple.
Copy this into a new tab to see: data:text/html, <html contenteditable>
So what I've come up with is really simple to use solution that will easily meet the needs of examiners, exams officers and students. Here is a setup guide and a video (6 minutes) below:
The setup guide includes 2 other versions with a bit of formatting and input fields that you may find useful. If you have a basic knowledge of html, you could customise your exam session however you wanted!