title: Stop watch app inventor
body: <p>I'm new user of App inventor. I need small stopwatch. Basic function:
   - set time ex. 25 min (if time=0;alarm=true)
   - start time
   - reset time (if you want reset time you will see the comfir box (yes or no)</p>
  
  <p>Can anybody show me what block I must use to create it ?. Sorry for my English.</p>