You will have to use the setSelectedIndex:
method of the UITabbarController
.
Eg:
Considering that your TabBarController object is named aTabbarController
[aTabbarController setSelectedIndex:0];
Now coming to the First Launch Ever, If you want the user to be navigated only during the First Launch and never again,
Use the registerDefaults:
method of the NSUserDefaults
Eg:
[[NSUserDefaults standardUserDefaults] registerDefaults:[NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:@"FirstLaunch"]];
if ([[NSUserDefaults standardUserDefaults] boolForKey:@"FirstLaunch"]) {
[[NSUserDefaults standardUserDefaults] setBool:NO forKey:@"FirstLaunch"];
[aTabbarController setSelectedIndex:0];
}