Mayo Studio uses in-app purchase to allow payments for the photo generation because the user is required to pay for each generation instead of a single time for unlimited generations. Using in-app purchase allow our users to pay as a generation-by-generation basis. We could not do that if the app was paid upfront.

Unfortunately, we cannot afford to offer unlimited generation with a single purchase as each generation requires to run powerful computers in the cloud for almost an hour which is an expensive operation.