We have compiled a lot of figures and we can tell you that there will be 3 million apps available on smartphones, tablets and computers at the end of 2013.
If you don’t believe us, please see below our numbers based on figures released by major stores (we made also some assumptions regarding missing data).
At mid 2013, 2.4 million apps are available on the 6 major stores (Apple App Store, Google Play, Samsung Apps, Windowsphone Store, Blackberry App World, Amazon App-shop)
We must add circa 150k apps available on computers at mid 2013, mainly on Windows 8 Store (please note that since YE 2011, no data are available for Chrome Web Store).
Therefore, the amount of apps available will reach 3 million at YE 2013 (+50% vs YE 2012).
Appgurus 