Gainback is an iPhone app developed by Jakob Hebenstreit. It falls under the Lifestyle category, specifically in the Food & Drink subcategory. This free app aims to provide users with a convenient way to earn rewards at participating restaurants and businesses.

Upon opening the app, users are presented with an overview of all the participating restaurants and businesses on Gainback. They can easily filter and sort these options according to their preferences. When selecting a specific restaurant, users can access detailed information such as opening hours and menu offerings.

To create a partnership with a restaurant, users first need to register with their personal information. They are then prompted to take a photo of the restaurant's ambiance or food. Automatically, a sticker featuring the restaurant's logo is added to this photo, which is then redirected to the Instagram story creation screen. After successfully uploading the story, users need to upload a receipt as proof. Gainback verifies the submission, and upon approval, the promised amount is credited to the user's account in the app. The accumulated funds can be withdrawn once they reach a minimum balance of $10.

In addition to its core features, Gainback also offers a map function to simplify the process of finding restaurants nearby. This feature enhances the user experience by providing a visual representation of the available options.

Overall, Gainback is a user-friendly app that allows users to earn rewards by promoting and visiting participating restaurants. Its seamless integration with Instagram and the ability to withdraw funds make it a convenient choice for those looking to save money while enjoying their favorite dining experiences.