Feature Request: Google Calendar Check

Hi,

I have been using Appointments+ for a while and I can say it is amazing. The practical limitation to this plugin is that I need to manage all appointments through the calendar to keep the availability up to date.

What I am suggesting is this:
Why not have the plugin check with one/more google calendars in order to set the availability automatically (since not all clients make appointments through the site).

Thank you
A.