Group calendar invites?

[clemsondave]

I found an app that will group contacts, Easy Group. It's a bit buggy, but works. However, it will only allow group messaging and email. I need a way to send out invites in calendar to a group. I have a group of apx 14 people that I send regular invites to. Selecting one by one is not fun. iphone 4s and Windows. Calendar is on a gmail account. Any ideas?