The Greggs App offers various rewards for its users. By scanning the app at the till, customers can earn free rewards and skip queues with Click + Collect. The app also helps users find the nearest Greggs shop. Additionally, by purchasing products, customers receive stamps in different categories such as sandwiches, sweet treats, hot drinks, and bakes. Once nine stamps are collected in a category, the tenth item in that category is free. Overall, the app aims to reward customers for their loyalty and provide value to Greggs fans.