Would it be possible to qualify the specific actions that would help growth in usage? I.e. correlating this dataset with specific "marketing" patterns such as use of push notifications, share buttons, etc.

How much does the app quality (ratings) correlate with usage patterns? If we assume that most apps aren't very high quality or don't bring much value to user, these findings would be kind of obvious; users find out that app isn't worth it and stop using it.

Overall, it would be interesting to know which apps break this pattern and why.

Correlating the data with marketing efforts would be nice and definitely provide more value but the apps we analyzed have little to no marketing budget (although there are some popular ones). This analysis actually shows the importance of marketing and promotion efforts since without them this is how an app ends up.

We will be doing similar analysis in the following weeks and hopefully will provide more detailed insights.

Some interesting stats.

Is this just in the Apple app store? If so do Android versions of the apps in question also see similar trends?

Yeah its just App Store. We didn't really have a chance to bundle such stats for Android apps yet but I'm pretty sure the results will be pretty similar.