A program to group files and applications into folders, just like on a phone?

I'm relatively new to customizing my desktop, I have a few widgets, a custom taskbar, and wallpaper engine. I wanted to know if there’s a free app that lets me group files and apps based on usage (gaming, work ...) basically like the folders on smartphones, where clicking on one opens it to reveal the apps inside. I’ve looked at options like Stardock Fences or iTop, but most are either paid or free with paid features.

Also, what app do you recommend for improving customization?