Ask HN: Review my latest project, DialShield

This is one of many side projects I started years ago and just this week decided to get off my todo list by finishing it properly and releasing.

DialShield is an embeddable widget and API for adding phone verification to a website or app. It calls/texts the person right from your website with a code they repeat back to prove they own that phone. Now you can tie a unique/traceable piece of identity to the anonymous web user.

It can be used to stop:

- Spam/duplicate registrations. Craigslist requires phone verification before posting in a high-spam category.

- Payment fraud. I registered this domain and built the API in 2008 (intending to eventually have people other than myself use it). I had a website with so much fraud from eastern-european countries using stolen credit cards that I lost a merchant account and was at risk of not being able to accept credit cards for the rest of my life. Adding phone verification to checkout cut the chargebacks from 15 a month to 5 all year.

- Two-factor authentication for login or password resets.

I'd appreciate any feedback. I don't have a friend outside the US so haven't been able to do much testing of international calling. I'd love to find out there's an easy way to get a phone number in another country that forwards to me for testing at little/no cost.

Built with Symfony, Twilio and Twitter Bootstrap.

I just tested it calling to my cellphone from Colombia. It worked like a charm. I'll definitely use this in a future project whenever I need it!