Name Product: Two-Way SMS WordPress Plugin
The Two-Way SMS WordPress plugin creates an SMS dashboard connected to any twilio account. (Twilio.com is the phone/sms provider). It allows your client to send and receive sms messages from multiple customers from one, easy-to-use, interface. You client can even speak their replies into the plugin if they are using the Google Chrome web browser (and have a microphone).
Each WordPress SMS user login can have their own twilio credentials connected to it. It can be their own twilio account or a subaccount on a twilio account.
It can be used in conjunction with any other twilio plugin.