Popular App Store tracker App Annie has released its latest report, and the news is good for iOS developers. Not only is iOS revenue up in general (by about 20% year over year), but it's still about three and a half times higher than Android revenue. Both Apple's App Store and Google Play saw big revenue increases in the latter half of last year, as you can see above, but iOS is still clearly much higher, which is definitely one of the reasons developers are so keen to be on Apple's platform in the first place.
It's notable that the top apps on the App Store aren't games at all: Apple and Google are the two top companies with the most downloads on the marketplace, and they don't produce any games at all. But in terms of revenue, games are still the biggest moneymakers on the store, and companies like EA, Zynga, and GREE are definitely picking up plenty of revenue. It's interesting to note that some of the companies on top of the revenue list are still only running one or two games, so as big as the App Store is, any developer out there with a big enough hit still has a chance to make the top revenue list.