Sending SMS with Facebook API
I've been looking for any example or documentation about sending sms through facebook API but couldn't find official one.
I've also read some somewhere that SMS has been deprecated from facebook API. Then why is it still available in extended permissions?
Here's some documentation about it on facebook: Facebook developers
It has been deprecated, insofar as it is part of the Legacy REST API, which while still functional, is being phased out in favour of the Graph API (and, to an extent, FQL).
I suspect that the permission remains in place so that developers have time to update applications that still use the REST API.