Most of the time you can find right plugin or widget end etc for open source CMS you choose. When I started to run a new wordpress web site for a business, I thought there would be a widget out there that can show list of categories in sliding mode. But there was not such a thing. Actually It was not what I wanted. So I googled and got to some customized widget that show categories as plain or listed in widget. I picked one of that codes and developed it further to make is sliding also make it RTL so it can be shown in right-to-left templates.
The main code I found was this.
I am not a php or even wordpress developer, so I read wodpress docs and learnd how to use js libraries with my plugin. For sliding part, I used nice and neat jquery library called owlcarousel . But I changed it a little bit cause I used it in a RTL theme. Also to show images with categories, I installed ‘Categories Images‘ so I could use category image in my widget.
You can download the plug-in from here.