In some implementations, a system provides an interface for receiving input for creating a customized module configured to provide a customized set of interactions through an application. The system receives data indicating desired functionality to be provided by the application after receiving the customized module. The system identifies one or more elements from a repository and a particular set of existing features of the application. The system generates a customized module to cause the application to provide the desired functionality indicated by the user input. The system provides the customized module to a client device that has the application installed, wherein the customized module adds the identified one or more elements to the installed application and causes the installed application to enable the particular set of the existing features.