iOS formatted String For Duration

- (NSString*)formattedStringForDuration:(NSTimeInterval)duration

{

    NSInteger minutes = floor(duration/60);

    NSInteger seconds = round(duration - minutes * 60);

    return [NSString stringWithFormat:@"%d:%02d", minutes, seconds];

}

- (NSString *)stringFromTimeInterval:(NSTimeInterval)interval {

    NSInteger ti = (NSInteger)interval;

    NSInteger seconds = ti % 60;

    NSInteger minutes = (ti / 60) % 60;

    NSInteger hours = (ti / 3600);

    return [NSString stringWithFormat:@"%02i:%02i:%02i", hours, minutes, seconds];

}