Share image/text through WhatsApp in an iOS app

NSString * msg = @"YOUR MSG";
NSString * urlWhats = [NSString stringWithFormat:@"whatsapp://send?text=%@",msg];
NSURL * whatsappURL = [NSURL URLWithString:[urlWhats stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
if ([[UIApplication sharedApplication] canOpenURL: whatsappURL]) {
    [[UIApplication sharedApplication] openURL: whatsappURL];
} else {
    UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"WhatsApp not installed." message:@"Your device has no WhatsApp installed." delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [alert show];
}