In the world of "mobile first, web second" we are seeing a significant uptake in mobile engagement across our entire portfolio. I think this is only the beginning. If you follow the trends out a few years, it could well be that mobile usage of many internet apps will surpass web usage. This is already the case with apps like Foursquare and Instagram. But think about apps like Facebook, Twitter, Tumblr, and Yelp. I can see all of these services having more usage on mobile than web in the not too distant future.
This shift to mobile usage will not be limited to social and local media. I think it will impact every service on the web in some sense. Ecommerce will be affected. Streaming media will be affected. News will be affected. Etc. Etc.
Most everyone uses some form of web analytics these days. Most likely you are using Google Analytics and possibly a lot more on your web app. But are you doing the same thing on your mobile apps? If not you are flying blind. Furthermore, you are missing out on a lot of usage that your employees, investors, and the "market" might want to know about.
Whether you use Flurry or some other mobile analytics solution, you need to instrument your mobile apps. If you don't you are missing out on a significant amount of usage and it will only grow over time.