Twilio's Big Day on Wall Street

— -- Twilio -- the calling platform used by popular apps including Uber and Whatsapp -- surged in its Wall Street debut this afternoon.

While the San Francisco-based company may not have mainstream name recognition, chances are you've used their services.

Twilio makes communication software that helps companies communicate with their customers anonymously. For instance, when a customer wants to find out where their Uber driver is parked, they can message the driver without either party having to reveal their phone numbers.

Signing up for a new app or service may require two-factor authentication, such as a verification code sent to your smartphone. Many of those codes are sent via Twilio, which counts OpenTable and Airbnb among its clients.

Trading under the symbol TWLO on the New York Stock Exchange, the company's debut marks the first U.S. venture-backed IPO this year. Twilio announced a $15 per share price on Wednesday. The company's stock opened this morning up more than 60 percent, at $23.99, before surging to a high of $29.20 this afternoon.