I'd like to know how many are solely focusing on Android development, with no website or iOS app to drive synergistic use. (Facebook app is worthless without the network effect from the website, and I wonder how well Angry Birds would do if you erase iOS success)

Last year Rovio said that they earned the same by ads on Android as iOS. Nearly 1 millon a month.

And I know a China team called Droinhen has good revenue from Play market

Various reports say that users on the App Store are more likely to pay for apps than Google Play users. I don't know what the reason for that is but that's the way it is for now.

If you want to make money from apps you should really be releasing on both platforms.

One idea might be to release free-to-play (ad supported) apps on Google Play. If you get enough adoption of your app, you can earn pretty good ad revenue.

yeah was reading this also , mainly because iPhone /mac users are more educated to pay for software and also because the payment method in apple is more intuitive and easy

Well, there are several people who make 2000-3000$ per month off of a couple of apps. Not a great salary, but I could live off that.

this is what i meant as side job , but if someone doing it for full time it will be great to hear , also the technical side of things

I'm too interested in this, As far as i believe, its very difficult.