title: CountDown Timer ios tutorial?
body: <p>I'm making an application where the exams is going on, so when exam start the, time should start with that. For example 30 minutes and it should reduce like 29:59.</p>
  
  <p>How can I implement this?</p>
  
  <p>Can anyone please give me a sample example or a easy step by step tutorial that i can follow?</p>