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THIS MOD that I find very useful. I use it.
I also use the
horiozontal (and I also bought the vertical) flyout menus from PhilJ. This is a CSS solution that eliminates the need for "fancy categories". Yes, you could do it yourself, but it's easier to buy it from PhilJ.
Used together, you can assign a single product to a single category, and when the customer selects the category, it navigates to the single product detail page.
You don't need PhilJ's category menus to make this work... if you're satisfied with the look and feel of the stock cat menus, then you're ok with just the first mod.
It works well in 4.1.3
How cool is this?