Option 1 - Use Mac Calendar.app as your calendar
This means that you will need to use the Mac Calendar.app (and not Outlook for Mac 2016) to manage your calendar and keep it synchronised between your iPhone/Android smartphone, computer and LawTap. See also:
Option 2 - Use Microsoft Outlook 2016 for Mac
Option 3 - Migrate from Google to Microsoft Office 365 Business Edition (e.g. Business Premium)
BOAB IT, as the trusted IT services provider for the Australian legal industry, is available to perform law firm user migrations from Google to Microsoft Office 365 Business Edition subscriptions at low cost.