Blog category list customization

I want to order our category list according to the interest of those browsing our site. How can I over ride adefault of order by name? The template that I am using does not provide the ability to change this choice. Nor do I find anywhere in the code where I can change the parameters. All information that I have found in searches are about 4 – 5 years old. Is there a plugin that will work with all templates? Or what code do I need to enter and where?