As Apple kicks off its keynote presentation at WWDC 2013, CEO Tim Cook is onstage sharing a variety of stats on the health of the company's various platforms. There are now 900,000 apps in the app store, with 375,000 of those fully optimized for the iPad. Out of those 900,000 apps, Cook claims that 93 percent are downloaded every month. That's up from 700,000 apps announced at the September 2012 iPhone 5 event, with 250,000 iPad-optimized events announced then as well. Of course, Cook touted the 50 billion apps downloaded from the store, which the company announced back in May. As for iCloud, Cook mentioned that the company had sent 7.4 trillion push notifications and has 300 million users with iCloud accounts using iTunes in the Cloud service.

As this is a developer-focused conference, Cook also said the company has paid out $10 billion to developers, with $5 billion paid out in the last year alone. Apple claims that this makes up 74 percent of total app download revenue across all mobile computing platforms, with 20 percent of total revenue going to Android developers.

Cook's also sharing some info on the health of the Mac platform — he said that the Mac install base numbers 72 million at this point, and that the MacBook and iMac are the top-selling laptop and desktop platforms available. As for OS X 10.9, more than 28 million copies have been sold since it launched last year; about 35 percent of total Mac users have upgraded to Mountain Lion.