Any plugins for smoothing out and making 3d models more print friendly?

ArsenyZvonar

Sometimes, when I browse Thingiverse and other resources I find models with really specific geometry. They're all very smooth, there are no tiny details or very sharp edges. Just perfect for printing in small sizes. But then I find exactly same models, but not smoothed out. Like a regular high-poly model with shit ton of details. This makes me wonder, are there some kind of plugins that turn regular models into such print friendly ones? Or do people actually model these from zero?

Here's what I'm talking about. The geometry really looks auto generated.
Regular Freelancer: https://www.thingiverse.com/thing:391029
and smooth Freelancer: https://www.thingiverse.com/thing:790364