Why?
Because of jailbreak and get game by free?
More user buy game than Android user?
Thx.
Because iOS users have already demonstrated a willingness to spend money frivolously by shelling out extra dough for the privilege of using an Apple product. 
Apple products are targeted at people who are more likely to be willing to pay for things, and Apple tries very hard to keep us in the habit of making small purchases.
Compare the price of an iPhone to an Android, then compare the practical differences. iPhones may be a little nicer (though even that’s debatable), but really we’re paying a premium to get an Apple product. On the other hand, people who buy Androids are likely to have done so at least in part because it’s cheaper - which means they’re more likely to be money conscious.
A part of the reason that people are willing to pay the Apple premium, though, is that Apple provides a far more consistent experience. Performance and quality on Android is far more variable than it is with iOS, so I expect that people feel more confident buying on iOS than on Android because we know that Apple won’t let something through if it’s not at least usable on the small number of devices it targets. On the other hand, on Android I have no idea if the device(s) they tested on are anything like the one I want to play on, and nobody at Google is screening out the crappy apps that don’t perform to increase my confidence in purchases.
I think it’s mostly because Apple has a much more controlled marketplace. One part is that there is much more quality control and no very low quality apps on iOS. Google is a bit more lenient about that and the store is full of clones.
So overall, how much more profitable iOS than android? 2 times, 3 times? or?
I read an article recently that stated game apps on iOS last year were 3.5 times more profitable than Android.
How long is a piece of string?
It really depends on a lot of factors, so there’s no solid answer to that.
There are also cases where Android turns out more profitable than iOS.
And Android is not just Google Play. There are way more market places.
That also may be part of the problem 
Absolutely
It variates a lot, it is rare but happens that a dev claims Android made them more money (never heard a 2x claim or higher in favor of Android)
iOS can be all the way from 2x to 10 or 20x (in my case, I was at around 15x) Heck, I made more money off the Mac version than I made off the Android versions (about 9x more)
Its not so much that iOS users are willing to pay, as much as Android users not being willing to. There seems to be some people willing to spend money on the Nook, but the install base is not high enough to make it highly profitable. Amazon… can be tricky.
I think you can make more money per installed device on Windows Phone and PC than Android. Problem is that Win Phone still has too small of an install base (so due to install base Android may still beat it, but have not experimented there to say for sure) and Windows only now got a native app store (that I still have not tested either due to Unity still not working with it.)
one more thing: this is not just about paid apps.
Free apps with in-app-purchases also tend to see a larger profit from iOS users, and Ad based apps are usually running ads for paid apps, or apps that will eventually profit from in-app-purchases themselves. Due to this, ads pay more in iOS than Android.
Concur with Stars and others. Recent threads and studies seem to indicate a 2-5X increase in sales on iOS vs Android. Which is why I’m holding off my Android port till later in the year.
Gigi.
Some of it’s chicken egg, some of it’s the nonstandard hardware and multiple OS targets, some of it’s the marketplace, some of it’s the piracy, some of it’s the type of users and some of it is simply that Android came out later. I don’t think you can pin it all on one particular reason.
I guess it depends on your sales overall but at the very least you can consider Android to be the advertisement for your real product on IOS (and other platforms).
Not quite.
The best games come out on iOS first 9 times out of 10, because apple created a walled garden where people can trust their money being spent on the latest AAA apps. Apps that just don’t go to android. Android gets chickenfeed and tests because of effectively, zero DRM.
Google is now fixing that with DRM though, more is coming. As a developer I have no preference which gives me a clear perspective.