The App Annie blog publishes mobile app market data, including download and revenue comparisons between iOS and Google Play.
HN commenters cite its quarterly market indexes for numbers on iOS versus Android revenue and why developers often build for iOS first.
It's not market share - it's revenue, demographics, usage patterns, and time to market that encourage iOS first over Android. While it is true that Android crushes iOS on global market share, the other factors are reversed in iOS's favor. For example: http://www.businessinsider.com/ios-android-shopping-2013-12
Intuitively, this makes a lot of sense. Many Android phones are substantially less expensive than comparable iPhones, and thus act as a stand in for an old Nokia or Ericsson. Those users that purchase inexpensive Android phones often aren't using it as a smartphone - it's just the free or cheap phone they get with their contract, and the use it as a phone first and foremost. This is in direct contrast to the iPhone, where Apple's advertising de-emphasises the "phone" part of the equation.
This is further evidenced by the fact that expensive Android phones see comparable (or better!) engagement as compared to iPhones: http://info.localytics.com/blog/top_of_the_line_android_phones_show_40_percent_higher_engagement_than_iphones
Also, keep in mind that the HN crowd is mostly interested US/Valley companies. Mobile market share numbers in the US are very different than global market share numbers, which leads to a lot of iOS first development in the US: http://www.comscore.com/Insights/Market-Rankings/comScore-Reports-January-2015-US-Smartphone-Subscriber-Market-Share Hence why so many apps on HN seem to be iOS first.
All of this having been said, if the rising trend in…
Last 12M ending 9/30/2015 (last available financial data): Google did $71.7Bn in revenue and $14.7Bn in net income. I assume the lawyer meant that Android had generated $31Bn since inception, but that can't mean gross revenue since they only take a 15% cut on the Play store (so wouldn't be able to show $22Bn of profit (71% margin). So $31Bn in net revenue implies $207Bn in gross revenues. The Apple App Store did $20Bn in 2015 and generated 75% more revenue than Google (http://blog.appannie.com/app-annie-2015-retrospective/), implying $11Bn in gross revenue for Google Play, or $1.7Bn in net revenue in 2015.
tl;dr: Oracle lawyers are full of shit
To put some numbers on it, according to this research (http://blog.appannie.com/app-annie-index-market-q1-2014/), relative app revenue numbers have been something like:
Q2 2013: Apple +230%
Q3 2013: Apple +210%
Q4 2013: Apple +110%
Q1 2014: Apple +85%
Android's market share (especially in emerging markets) is exploding (https://s3.amazonaws.com/files.appannie.com/reports/App+Annie+Special+Report+Google+Play+2014.pdf), while Apple's app store revenue are substantially flatter (http://images.apple.com/nl/pr/pdf/q2fy14datasum.pdf).
Apple's definitely on top right now, but the gap is narrowing very, very quickly.
Every single indicator is trending away from Apple here, from number of app downloads, to overall revenue, to revenue per-app. It's still in Apple's favor, but the gap is narrowing quickly. I've seen a very dramatic change in the attention devs feel they have to give Android even in just the last year.
Maybe this won't continue but if you're skating to where the puck will be then it doesn't look so much like Apple right now.
http://blog.appannie.com/app-annie-index-market-q2-2013/
There's some evidence of that here: http://blog.appannie.com/app-annie-index-market-q2-2013/
People on iOS are more willing to buy apps and do more in-app purchases but the gap doesn't seem that wide to bridge, especially as iOS users move to Android.
UK is about 30%, Australia around 28%, China around 20%. US, Japan, China, UK and Australia were topping iOS App store Revenue in Q3 2013.
http://blog.appannie.com/app-annie-index-market-q3-2013/