I created it using the demo, as I've just installed it. I've taken a look at the pricing and an indie license costs 99$. I'm not sure if it's worth it. The good thing is that it has different settings to get the result you want:



I'll take a look over the internet to see if I can find a good plugin for Gimp. Currently I have one based on the nvidia plugin for photoshop but it doesn't allow to customize as good as crazybump.

Edit: after taking a look I think there's just one plugin available for gimp, but I've seen some videos in which they later modify the result using different filters, maybe that's the way to go