Freedom Cry is Assassin's Creed IV: Black Flags main story DLC that released back in December. In the story DLC you stepped into the shoes of Edward's first mate Adewale. The DLC offered up a new perspective on the game from Adewale's point of view. The DLC is apart of the Season Pass.
Today Ubisoft has revealed that they are going to release a standalone version of Assassin's Creed IV: Black Flags DLC, which is titled Freedom Cry. The standalone version will be releasing on February 18, 2014 in North America and February 19, 2014 in Europe. You will not need to own Assassin's Creed 4 to play the DLC. It will be priced at $15.
Source: PS Blog.