This article describes the aggressive cache in EloView 3 WebApp settings. 

The Aggressive Cache feature will download and cache jpg, jpeg, png, gif, ico, js, css, woff, tff and eot file resources, so that they can be used without needing to download them again.

With Aggressive Cache enabled, the WebViewController will first check if the resources are downloaded before requesting them from the server. If the resources are downloaded, then the controller will use them.