Let's start with the beginning:
- The number of apps crawled is not that relevant as long as the number is large enough so there is no reason to talk about it.
- I'm not so sure about that small number of comments for the iPhone Apps, but then again, the Apple App Store is built differently from the Android Market:
2. Default view on Apple App Store is "Reviews on the last version" while the default for Android is "Reviews for all versions."
- Average rating is similar for both stores so no real surprise here.
- Average price is higher on App Store. Why? The registration fee for Android Market is 4 times smaller than the one for Apple Developer Program. The price tiers are fixed on the App Store while on the Android Market they are way more flexible. And on top of that, it's a decision made by each publisher. They seem to think that an iOS user pays more for an application and apparently, they are correct.
- Max price is irrelevant.
Now, let's analyze some of the app categories that show discrepancies between platforms:
Well... it's hard to say but in my opinion the fragmentation of Android is the most important factor. I've low rating from users because their phones are not supported by the apps, because the apps are not that well implemented for their phones/tablets. It's a lot harder to make an app that works on most Android devices than it is to make one for all iOS devices (simply because there are more of them).
Health & Medical: small advantage for iOS, but I think it can be explained by the fact that iOS users are more health conscious (it's widespread knowledge that Android appeals to the more than average technical user and iOS to people with above average income), and the apps are more easily made on iOS to suit them.
Weather & Tools: Medium to large advantage for Android. I'm going to add these both in the same category because the underlying cause is the same here: iOS is a closed system, compared to Android. iOS developers have less access (mostly none) to system information, settings, etc than Android users. For tools, it's hard to make an useful tool for iOS (most of the ones from the App Store are battery charge estimators), when you don't have access to modify or even read system settings. For weather apps, the lack of widget capability is clearly a drawback for iOS, as weather apps aren't apps an user wants to click, open and close. They want a widget, similar to the HTC Sense one, that shows the weather at a glance.
Going on to the last part of the infographic and probably the most interesting one for developers:
Install problems: Here, the Andoid fragmentation shows it's ugly head again. With so many different devices and Android OEM mods (like Sense, Motoblur and the rest) a lot of issues slip through the cracks, leading to installation problems.
Pricing: as it seems, the most important complaint on iOS. Can't say I disagree with it, though, if we compare the prices on iOS and Android with prices on handheld game consoles(like the PS Vita or the Nintendo 3Ds), there shouldn't be so many reasons to complain about the price. I admit, there are publishers with ridiculous prices on their apps (like Square Enix for example), but the most bought apps and games the the $0.99 ones.
Performance: Same issue again, fragmentation. The quality of hardware and software modifications on Android devices is appalling, if you go out of the normal range of Android sellers: Samsung, Motorola, HTC, LG and even Sony. Variations in GPU's, in CPU's, in SD Card quality... all of this makes it hard for a developer to optimize.
Crashes and hangs: Same, same issue. I'm gonna stop talking about fragmentation and start looking at some of the numbers from iOS. What might make some people wander is the really small amount of "hang" issues, but in fact, it's relatively easy. This is how the iOS is built. It's built not to have apps hang. It has relatively low timeouts, closing the apps when they stop responding for a fair amount of time. It's harder for the users to spot these hangs and it has a proper reason for this: making the system look more fluid. Every iOS users that I've talked to made this as the deciding factor when they bought their device: the smoothness of the system.
UI Controls: Here, the screen size for the Apple devices (let's exclude tablets from this discussion) is a drawback. It's harder to design the UI and the controls to match a smaller screen, than it is to design them for a Xperia Play or a Galaxy S II.
Security and privacy: This mostly to the perception of the users, and it's not relevant as both systems have had and will have problems with security and privacy. See Carrier IQ, Android Malware, iPad 2 Smart Cover hack, etc.
Thank you very much for taking the time to read this and thanks to uTest for this really interesting graphic.