My wife and I have played Parallel Kingdoms for a long time and found it very innovative and gave us our online fantasy RPG fix. Although they have released some improvements and updates since it's initial launch the game clearly lacked depth.
Now with their new update it's a highy polished MMO with tonnes of features, stability and game depth. As of today it is now the second Real MMO for the iPhone. It has a great site with a useful guide that explains all and is accessible from directly inside the app:
Parallelkingdoms.com
I rate the game now at 4/5. It can still use more content (and push notifications) but is a solid MMO.