Oh, that. It’s true that it’s similar and it’s not bad either, but I really like the kind of insight Filelight gives, with its folder sunburst view especially. It’s more complete, since it shows everything, not just what it thinks I should get rid of.
Disky, mentioned by others, is the closest to that, as far as I’ve seen. It’s really good and you can have the same experience on it regardless of the ROM you’re using, since it’s just a normal app instead of a vendor dependent system app