I started using https://www.crittercism.com for crash reporting of my photo frame app. It only makes the app 40 kB bigger (peanuts on a 1Mb app) but sends the stacktrace automatically to their servers.
Where I normally receive one or two crash reports a day, it was soon clear to me that the problem is a lot bigger than that. Thanks to the detailed stack trace, I was able to resolve most of the problems really quick.
On a daily basis I have 300 people checking out my app but only 100 or less keeping it. Now it is clear to me why. Most of these users run into a crash that does not occur on my test devices. I hope the number of users that keep my app will be higher now and that the current users will have a more stable app.