显示秒表计时器动画，如汽油泵表使用NSTimer。

I am new in iOS developement.When I press the stopwatch start button I want to display the timer like counter token effect.I have attached image for your reference.I have done to display secs and minutes but I dont know, How animate autoscroll effect? How can I do this?I am new in iOS developement.When I press the s