DigiCal is only available on Android, so it is currently not available on a PC/ Mac or iOS/Windows Phone. You will need a calendar server like Google calendar, Outlook.com or Exchange to sync with your mobile devices and computers.
Assuming you're using google calendar, you will need to set-up a Google account on your Android device. On your PC you can either use the web version www.google.com/calendar to manage your appointments or use Outlook. If you add your gmail in Outlook, you will be able to manage your calendar as well.
How to sync Outlook 2010 with Google Calendar?
DigiCal makes use of the default Android calendar system, which offers numerous syncing options to different calendar servers such as Outlook.com, Exchange or Google Calendar. Normally you will first need to check out with which calendar server you are connected in MS office outlook, so you know what kind of account you need to setup on your Android device.
Here's a help page explaining how to do that:
How to configure Outlook to connect to an outlook.com email account