I can't comment on their mobile offerings, but OMGPOP has been running a fairly unique web-based online gaming platform for years. They certainly had a fairly large userbase when I was using the site a couple of years ago, but I guess the facebook and mobile apps were the ones that really brought users.

The web platform has made a number of moves to monetise in recent years, putting more and more features behind payment-based tokens. It'd be interesting to know what proportion of their income comes from the web gaming platform.