Webkinz Friends was an online social game that was hosted mainly on Facebook and mobile app stores. It launched in 2012, and on July 29, 2014, new members were unable to make new accounts- with August 31st, 2014 being the final shutdown period for all players. However, the Facebook page for the game is still available, and you can view it here.
The official Facebook page states: "Webkinz Friends is a social game where you can make a big happy family in the Kinzville of your dreams, with the added benefit of sending prizes to anyone in Webkinz World! Ganz brings the fun of Webkinz to Facebook with a new social twist, enabling parents and teens to build the Kinzville of their dreams with the added benefit of sending prizes to any Webkinz World account from Facebook."
This game has many similarities to both the original Webkinz World and other popular Facebook games or social mobile app games. These include games such as Farmville and Dragonvale. There are goals to complete which supposedly granted you items and kinzcash, and buildings would generate revenue which you could then use to build more decorations and buildings. There was also an option to send exclusive items from Webkinz Friends to your Webkinz World account. You were also able to befriend others through linking your Facebook account to the game, allowing you to visit other towns.
Note: There are also other currencies, but the use of these and how to earn them is unknown to me.