Send SMS to Google Group

I have a Google group of contacts setup (that is, it's a group I created and stored using my Google account). I'd like to send an SMS message to the group from my iPhone 5s with iOS 8. How can I do this with free apps?

In other words, I don't want to have to add people individually to the SMS message. I want to just choose the group (from a list of groups obtained from my google account), and the app will automatically add the members of the group to the SMS recipients.