The ActionTimer.exe was used for the old Win32 and WinCE clients, using the Agentry SDK. This wouldn't work for the WPF, iOS, or Andriod clients.
For the WPF, iOS, and Andriod clients you will need to use the Open UI controls. On your main screen have a field that calls out to the openUI control. Then you can have the OpenUI control start a timer and call back to the client every X minutes and have it call the action you want.