Dial number from your app without any default interaction and UI of iPhone/iPad.

Just copy and paste this below method in your implementation class.

-(void)dialNumber:(NSString *)number{

    number = [@"tel://"stringByAppendingString:number];

    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:number]];

}

and use this method with your dial number for ex.

 [self dialNumber:@"9033634116"];

When you call this above method with any phone number, that phone number automatically dialed from iPhone/iPad.