This is not a material change, which is a good thing. To us, the steady growth rate indicates that the app economy is not yet experiencing saturation, as consumers steadily use more apps over time. And while there are more apps in the store, large numbers of them have short lifespans, such as books, shows and games.
Assertions that people are using fewer apps in 2012 than they did in 2010 appear to be incorrect. While one could observe that consumers use only 8 apps per day among the million+ available between the AppStore and Google Play, one also needs to remember that the 8 apps each consumer uses varies widely.
This creates a marketplace that can support diversified apps.