In the instant messenger from Google Hangouts many users wanted the implementation of the possibility of sending SMS, and the company has promised to fulfill these requests in the near future. Hangouts - a universal means of communication, in lieu of all other services, lacking only sms. Apparently, Google had planned from the outset to add application support for SMS.
This confirms the fact, request permission to send and receive text messages when you install the program. When exactly will be implemented this function is still unknown.