Very useful as it's very customizable and native touch support is hard to discover in Firefox on Linux...
When setting the envvar MOZ_USE_XINPUT2=1 and the about:config setting dom.w3c.touch_events.enabled to 1, Firefox's built-in touch support is enabled and allows websites to distinguish between your finger and mouse pointer.

Good

I like this feature so much that I wonder if there is similar software for Windows, and I want to use it outside of the browser.

Hello! This is a really useful add on, especially when browsing with pen tablet. Although there's one thing that I think needs to be added. Could you create a new option to set how far the cursor needs to be moved after the scroll button is pressed to actually start scrolling? So for example, if the value for this setting is 10 pixels, that means the cursor wont scroll the page until the cursor has moved 10 pixels from its initial position. This will be useful for some websites like Twitter since it's very difficult to click anything there

нормально скроллит при зажатой кнопке стилуса thinkpad x230 tablet в линукс минт, юзать браузер в режиме планшета лучше стало.