Android:
Add the code below after initializing PushBots library: 

//First run
Pushbots.sharedInstance().registered(new Pushbots.registeredHandler() {
    @Override
    public void registered(String userId, String registrationId) {
        Log.d("PB3", "userId on PushBots :" + userId);
        if (registrationId != null){
            Log.d("PB3", "registration GCM Id:" + registrationId);
        }
    }
});

//Subsequent runs
Pushbots.sharedInstance().idsCallback(new Pushbots.idHandler() {
    @Override
    public void userIDs(String userId, String registrationId) {
        if (registrationId != null && userId != null){
           Log.d("PB3", "userId:" + userId);
        }
    }
});


iOS:
Add the code below to didFinishLaunchingWithOptions function in AppDelegate file:

//First run
[Pushbots onRegistered:^(NSString *userid) {
    NSLog(@"userId %@", userid);
}];

//Subsequent runs
NSString *userid = [[NSUserDefaults standardUserDefaults] objectForKey:@"com.pushbots.api.object_id"];
NSLog(@"userId %@", userid);

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