Palo Alto, California-based start up Tello has launched a new mobile app that lets you rate the customer service of any employee at any business in just seconds.

The launch of the fully social version of the service lets you directly engage with businesses to resolve issues, locate businesses nearby or in a specific area and share your ratings on Facebook and Twitter.

Whether it's a salesperson, a car dealer, a cell phone provider or a waiter - the app lets you thank them for great customer service, or give them constructive feedback on what they could’ve done to serve you better - all in 30 seconds or less on your smartphone.

The new app, which is free and available on the iPhone, iPad, Android and online, includes a “Request Reply” feature that lets you tell a business you have rated an employee and would like them to contact you to resolve any issues.

During our beta period, more than 85 percent of Tello ratings were positive — we think Tello can be a new kind of rating system that offers businesses structured, constructive criticism in real-time, says Tello chief executive Joe Beninato.

Tello, which secured $1 million in angel funding in the summer of 2010, is backed by a group of early-stage investors, including Jon Callaghan of True Ventures, Ron Conway of SV Angel, Mark Goines, Dave McClure of 500 Startups, and Eric Paley of Founder Collective, Shervin Pishevar of SGN, Naval Ravikant of Venture Hacks, Chris Sacca of Lowercase Capital, Aydin Senkut of Felicis Ventures and Russ Siegelman.

Tello also announced a partnership with Localeze, a business-listings provider for local search. Localeze's registry of 14 million U.S. businesses will help Tello users to locate nearby businesses.