Platform: Android, iOS Not really a replacement for one-on-one SMS, per se, GroupMe does send messages to groups of your contacts (for example, roommates, coworkers or Relatives I Typically Avoid) via a specially assigned phone number. That group—and its dedicated number—get stored in the phone's contact for easy retrieval. Any and all responses to the original message are displayed in the app. Previously, GroupMe worked exclusively over SMS, but now it's easy to switch between a smartphone's data connection (free) or the carrier's SMS service (paid). What's more, the app lets users send outgoing messages to other callers, however responses to those messages land in your regular SMS inbox, so get ready to pony up.