Symfony2 webapplication icon and assetic

Question

I am developing a webapplication using symfony2 as backend. I am trying to customize the aspect of the application on mobile devices. Reading IOS and Android documentation I collected the metas and links to put in the head of the page. For Android devices the manifest.json file should be provided. In this file the icons to be used must be specified. I would like to treat the manifest file and the icons as assetic assets. I think this will bring me to a problem similar to images inside css files (and the relative cssrewrite filter). Using {% stylesheets %} or {% image %} directive will, also, put my json file inside the css or images folder too. I would like assetic to generate Has anyone solved this problem before? BR Stefano