Looks like your app has an issue with startup time. Apple says that 400 milliseconds is a good launch time. If your app loads more than 20 seconds iOS will kill the process.
The main reasons of such issue can be:
- A lot of frameworks in the app
- Project has a lot of classes, categories
- Project is written in Objective-C (Swift has optimized runtime)
Try to add the environment variable DYLD_PRINT_STATISTICS
in Scheme:
You will find in console launch time statistics:

Also check -application:didFinishLaunchingWithOptions:
method in AppDelegate. If you perform some heavy operations remove them. You can measure code execution time like described here or precise methods described here .
For more information take a look at: