Works on iPhone4

I have not tried anything other than to create a few groups, and then use those to classify my contacts. This app works. Have not tried group text or email. The app is not real convenient to use to "group" a hundred contacts, and it quits after "grouping" a few dozen, but you only have to restart the app, no damage done.
-VooDude

4VooDude about Contacts Group Manager - GroupQ, v9.6