Stock Google Contacts app no longer supports contact groups. Chomp can still add those groups in a message but I can no longer edit those groups. Also, when I get a third-party contacts app to make new groups with the same name, such as "Classmates", and use Chomp to send a message to that group, I'll see 2 "Classmates" groups: the old one I made using the stock contacts app and the new one I made using a third-party app.