This is the app for you. You can setup and use a SMS-mailing-list just like its email counterpart.
When you send SMS message everyone instantly receives it. Best of all, group members can use any phone they want.
1. Host (the application owner), can setup a mailing list and add members from his address-book.
2. Members can subscribe (or unsubscribe) themselves to the mail-list by sending SMS.
3. Members can send SMS messages and all members will instantly receive it.
4. The mailing list can be uploaded to GoogleDocs-spreadsheet for customization and backup.
5. Users can send personalized SMS based on data from spreadsheet (see below)
Sending personalized SMS to group:
The app can be used to send customized to group members. For example
1. For example Sales Manager can send monthly sales target to his team.
2. Doctor can send appointment reminders to his patients.
3. Teacher can send test-scores to his students.