Secretly Find the Right Size with

In the midst of the Zappos Holiday Hack-a-Thon, developer Erik Dungan built an app to anonymously find out the correct size of your gift recipient using Twilio SMS notifications.

Erik posted on Hacker News for feedback, quickly shot to the top of list and received thousands of visitors over the first weekend.

A Zappos Shoe Collection Gives Inspiration

In under a week, Erik thought out his concept and built the entire app in just two days. He credits his wife who, with an impressive shoe collection, is a Zappos VIP, which got his e-commerce creative juices flowing.

Aside from some basic experimentation, was Erik’s first experience building an app powered by Twilio. After attending TwilioCon this past year he had been even more so inspired to build something that integrates telephony capabilities, and the hackathon was the perfect opportunity.


The key components driving are Zappos and Twilio SMS along with many other technologies that support the fine art of surprise gift giving. is built using Ruby on Rails and hosted on Heroku. For the web Erik is using Twitter Bootstrap for form styling and Google Web Fonts for type styling. To let the browser know when the gift recipient has replied, the browser redirects to a gift suggestions page using Pusher. And to send a follow-up email to the gift giver after using, Erik uses SendGrid.

When a visitor send an Anonysize request, the app sends their recipient a text message asking for their shoe size. When the recipient responds the sender will receive the answer via SMS and the site will update in realtime connecting the sender to a Zappo’s page of suggestions. The recipient will also receive a follow-up question that asks what kind of shoe he or she prefers. is the perfect solution for figuring out the right size for a gift without giving it away.

About this DOer

Erik is a a web startup veteran. He most recently co-founded two companies focused on web services for professional photographers, APhotoFolio and BIG Folio. His other project, Cilantro, builds HTML5 websites with Facebook integration for restaurants. Follow Erik on Twitter at @callmeed or connect with him here.