Bodypaint 3d is a full scale texturing application integrated into cinema 4d. In older versions like rel 9 you could install it as a standalone version. It can be used as a standalone with other 3d applications like Max or Maya too.
The real power of Bodypaint is the ability to use Photoshop brushes and paint directly onto the geometry.
However if you want to make proper displacement painting then you should make displacement maps in some special application like Zbrush, Silo or Mudbox.
Bodypaint is also a special tool for making uvmaps and has got great wizard tool for quick map generation. One should still know how to use projection types. Alternative tools for uvmap generating is Topogun.