Filterable cards

Hello,

I‘m very interested into working with grav but I need a feature that is basically like on the themes downloads page of getgrav: https://getgrav.org/downloads/themes

Is there any plugin that can solve the task?

Several themes do this, and there are a variety of JavaScript-libraries that facilitate it. For a basic, extendable approach, you can rip anything you need from the Project Space theme.