The term refers to a well-known uploader in the software cracking community. This tag indicates that the version is likely a pirated or "cracked" copy of Nitro Pro 9.
The 9.0.2.37 specifically was a maintenance patch. It didn't necessarily add flashy new features but refined the stability of the software, fixing bugs related to plugin integration with Microsoft Office and printing errors. Nitro Pro 9.0.2.37 -64 Bit- -ChingLiu-