Not just today, but back in September, as the record states, the Android Market reached its 500,000 app submissions mark, while just 315,000 apps sit out for sale today. The month of September 2011 is said by market research firm research2guidance to both be the home of that 500,000 app submissions market and a new record for per-month applications in the Android Market. This compares to what the Apple iTunes (iOS) App Store currently has for app submissions, 600,000, with approximately 456,000 apps in that market today.
These numbers add up, according to research conducted by Appfire, to be more than 1 million apps created thus far and submitted to the app stores combined, with under 800,000 available for download inside September. Appfire collected numbers adding up to 1 million and 800,000 independently of research2guidance, so we can expect the REAL numbers to perhaps fall somewhere right down the middle of the two findings. Why is there no perfectly clear number? Quite simply because apps come and go every day. With regulations in both app stores different on how app submissions are made, accepted, and eventually pulled from the market due to a variety of circumstances, there is no exact number outside what Apple and Google have behind the scenes.
On the other hand, research2guidance looked at Microsoft's Marketplace for Mobile in the same timeframe and found them to have something like 35,000 applications with an approximately 13% deactivation rate (per month.) Of course these numbers are subject to time as well, as Windows Phone 7 is still a young mobile OS compared to either Apple's iOS or Google's Android. And of course you've got to consider the fact that Apple's application and acceptance rate at which they bring apps into (and usher apps out of) their app store is much more strict than that of Google's Android Marketplace, and that many apps a fine app store do not make. Quality over quantity!