I would like to have a button for fast browsing. I tried to search it but there are too many extensions so I haven't found anything useful. Here is an example
listed category - many items I want to read
And when I want to go to the next article, I have to get back and choose it from the list. Can I have NEXT and PREVIOUS buttons in the opened article with an extension?
I have never seen such an extension.
There is nothing like it in the Category extensions category at mediawiki.org, which most probably means it doesn't exist or would be hard to find.
It shouldn't be too hard to write, though, so you can give it a try.
If I got the intended usage and placement right the OutputPageMakeCategoryLinks hooks should be the best place to start. Use the $out param to add HTML to your page just above the category list.
Good luck.
I think that the Hierarchy extension has the functionality that you are looking for. It provides several, but I think what you are looking for is called the horizontal method.