CLS_LOG
Use CLS_LOG in place of NSLog like this:
#import <Crashlytics/Crashlytics.h>
CLS_LOG(@"Higgs-Boson detected! Bailing out... %@", attributesDict);
You'll still get the NSLog debugging messages but in release builds you'll get the messages in the Crashlytics dashboard.
setUserIdentifier
To set an identifier to be shown with a crash log
#import <Crashlytics/Crashlytics.h>
#ifdef APPDEBUG
[Crashlytics setUserIdentifier:@"Development User"];
#else
[Crashlytics setUserIdentifier:[NSString stringWithFormat:@"Some ID: %d, Server IP: %@", (unsigned int)self.SomeUniqueId, self.RecordServerIpAddress]];
#endif
Other Features
See the crashlytics.h file