1. A computer implemented method for dynamically loading application code on a computing device, the method comprising: under control of one or more computer systems configured with executable instructions, receiving an application at a server associated with an electronic application store; causing the application to be installed on a computing device in response to receiving a request to install the application from the electronic application store; and injecting classpath modifying code into the application, wherein, in response to running the application, the classpath modifying code is configured to: identify an application type of the application, select one or more classes from a plurality of classes based at least in part on the application type, the one or more classes enabling at least one function of the application, and modify a classpath associated with the application to reference the selected one or more classes, the computing device being configured to retrieve the one or more classes to enable the at least one function of the application without requiring an update by the application.