ColorTab is the name of the notation software and web app I am creating during the pandemic. It is completely free, no strings attached. There is no business model. I am just a guitar player with an idea for a new way to create and use tablature notation. The app is phone friendly and works on any device, even with no Internet. I think it is easy and fun. It is useful for beginners and pros, has full playback functionality but with a new format with color instead of staff lines to indicate the strings. That makes it very compact, 5-10 times less screen space is needed compared to traditional staff with tablature. It can be printed if you need paper, and can be used on any size screen regardless of the song length.
To use the app offline, click the download icon at the upper left. A file named title.html (or whatever song title was entered) will download automatically. That file can be opened locally by a web browser and is self contained. Or just use the browser save page for the same result.