[subinsebastien]

Again, nothing new. I have already implemented this on my app here : https://play.google.com/store/apps/details?id=in.xtel.quitq.... using Twilio alone. But, twilio is not completely free.

[OJFord]

Well done. But you didn't blog about it, or release that part of your app as a standalone library. You also didn't (couldn't) patent it - it doesn't need to be new to be interesting and valuable to HN readers.