1. A computer-implemented method, comprising: storing, at a server, one or more application code blocks, wherein, when an application code block is executed on a computing device, the application code block causes a device-specific version of an application to be presented, and wherein the device-specific version of the application includes an interface that is specific to a type of the computing device; accessing a factor associated with the computing device when a webpage is accessed, wherein the webpage includes a code module that causes the factor to be accessed when the code module is executed, wherein a factor corresponds to a device-specific attribute associated with the computing device, and wherein the device-specific attribute identifies the type of the computing device; accessing a rule for selecting application code blocks, wherein a rule corresponds to a device-specific version of an application; evaluating the rule using the device-specific attribute corresponding to the factor, wherein evaluating the rule using the device-specific attribute includes selecting an application code block from the one or more application code blocks, and wherein the selected application code block corresponds to the device-specific attribute; and transmitting dynamic code, wherein the dynamic code includes one or more application code blocks including the selected application code block and an additional code block, wherein when the dynamic code is received at the computing device, the selected application code block is executed and the additional code block is not executed, and wherein executing the selected application code block includes displaying the application on the computing device according to the device-specific version.