Looking for Interval Timer with a Rest (or Cool Down) period at the end

Hi All,

I just bought a Forerunner 645.

I would like to install an interval timer or Tabata style timer, BUT I would like it to have a final rest period (or a cool down period) after the workout is completed.

Something customizable that would allow :  cout-in delay of 5 sec (to start the program) :: HIIT session ( 5x  20 sec ON, 10 sec OFF) :: Cool Down (final rest period) 2 minutes.

Has anyone come across an app with something like that ?