Works with CiviCRM 4.7 and should work on CiviCRM 5.0 or higher
This extension sends sms as a autoreply when Inbound SMS activity is recorded.
Screenshots (click to enlarge)
Since CiviCRM 5.x, extension releases compatible with CiviCRM 5.0 are compatible with 5.0 and later. An extension release compatible with 5.25, for example, means that it requires CiviCRM 5.25 or later.