Potbelly Sandwich Shop last week officially launched its mobile app, which features payments, order-ahead capabilities and rewards. 

Customers that download the app for either Apple or Android will receive a free cookie when they register for Potbelly Perks. Through the Potbelly Perks program, customers earn a "smile" for every $2 spent through the app that can be redeemed for tasty treats.

Customers can earn fun status levels, like Cookie Rookie, with personalized perks, Sandwich Superstar, with invitations to exclusive events and access to an underground menu, and Menu Master, with the permanent perk of a free cookie with any purchase from 3 p.m. to 5 p.m., according to a press release.

"Potbelly loves being our customer's neighborhood sandwich shop, providing good vibes and great food. Our new app is another way to offer our customers personalization and convenience on their terms," Dana Dimitri, senior director of integrated marketing and customer engagement, said in the release. "We're also very excited to now be able to give our loyal customers fun perks through the new app."

The app also enables customers to customize their meals, find their nearest Potbelly location and send digital gift cards. The free cookie offer can be automatically redeemed when new users download the app and register for the Potbelly Perks program. Customers can also sign up for Potbelly Perks online.