It is not clear what you mean. Revision slider is a tool designed for desktop users not mobile devices, so it is not clear why you're asking for "help". That is probably why it doesn't show up in the normal mobile view. This might require significant work. For it to work in a mobile device they need to change the interface to work with touch (and non-touch) based events and possibly reduce the number of revisions fetched due to smaller screen sizes and generally lower bandwidth.
Even then, it would probably still not work well using the desktop view. Although the older version kind of works, it still has issues, e.g. popups can't appear until clicked because there is no hover in most mobile devices, and having two diffs in a tiny screen makes it hard to read either of them.
This could be a feature request rather than a bug report ...