As the good folks at Flurry have pointed out, the retention problem facing most app developers is a much bigger issue than the discovery problem. Winning a download is excellent, but for every 100 downloads today, only 4 of those consumers will still be using your app a year from now. The drop off is exceptionally steep, with more than 60% of the initial customers giving up on the app in the first month.
There are several important steps to take in thinking about the retention equation. The first is that you need to measure it. We highly recommend instituting some form of metrics and management in your app, whether it's using Google Analytics, Flurry, Kontagent or building your own analytics, you can quickly understand at an aggregate level what's going on after someone installs your app.
Measurement is a core step to take in the process, but measuring doesn't actually impact the retention equation. In order to impact the equation, you need to be focused on updating and refining your app on a regular basis. As you learn about how people are using your app, what they expect from it and what they'd like to see in order to improve it, you have to listen to the feedback and iterate on your product.