Systems and methods for creating a customized digital publication are disclosed. For example, one disclosed method for creating a customized digital publication comprises receiving, at an application builder executed by a processor, a digital publication application shell comprising an application programming interface (API), the digital publication application shell specifying standard functionality or appearance features for a digital publication application, and custom feature code specifying a custom feature based at least in part on a reference to the API of the digital publication shell, and producing the digital publication application based at least in part on the digital publication application shell and the custom feature code, wherein the digital publication application comprises at least some of the standard functionality or appearance features specified by the digital publication application shell and the custom feature specified by the custom feature code.