It is free, currently it supports Android 2.3 or above.

Currently App provides following functionality.

• Send Messages to phone contacts
• Send Messages to your SMSzone Groups.
• Backup your Local SMS Inbox and Sentbox to your SMSZone account.
• Send SOS Message - our social initiative.
  Using this feature with a single key press, you can send your location details to your five contacts.

Visit Google Play To Download