1. A method for creating an add-on application, comprising: creating, with an electronic processor and in an electronic storage medium, an add-in definition object within an add-on application development environment, wherein the add-on application is based on a foundation application, and wherein the add-on application requires at least one function that requires code modification within a modified object of the foundation application; defining, with the electronic processor, a method in the business add-in definition object for the at least one code modification to provide the at least one function; inserting a call to the add-in definition object in the modified object; responsive to completing development of the add-on application, copying the add-in definition into the foundation application; and responsive to a new version of the foundation application being created, copying the add-in definition into the new version.