It could be a whole lot simpler than this. (And a whole less secure.) In high school I had a server running that scanned email for a keyword and my cellphone number; I didn't have a smartphone. So I texted a keyword and some code to my email. Then my server would read the email, see it contained the keyword, then interpret the rest of the code I sent and execute it. This would be insanely easy (and not too secure) to implement on Android for instance.
Then you misunderstood, or I am perpetually misunderstanding. The comment that I responded to asked for a way to use this product to send actual text messages. He wanted to relay a message to another phone via this product and then have his phone send an actual text message using information from the initial message. I gave a suggestion about how to do that.
