Words with Friends, the Scrabble-esque mobile app, is heading to Facebook, with the makers Zynga clearly looking to spread its user-base whilst adding more features into the mix.

Zynga, perhaps most famous for its Farmville game, as well as bringing Words with Friends to a whole new audience, is also making sure its core users are kept happy. Efforts to do this include notifications alerting you to invites and when it's your turn to play, along with the ability to sync past games. It'll also offer continuous play, allowing you to start on one platform and continue to play on another.

Launched in 2009 by NewToy, Words with Friends was snapped up by Zynga in late 2010. And whilst this acquisition-based approach to growth appears to have worked very well for the company, this port to Facebook highlights Zynga's continual and growing dependence on the social networking site. Indeed, it will be interesting to note what, if any, exclusivity clauses Facebook may apply in the future.

Given the past history of the two companies - with the relationship strained just a year ago over Facebook's insistence on Facebook credits as Zynga's only payment platform, of which it takes a large percentage for using - it's a wonder that the two are still speaking.