Hello everybody, I've got a question and I didn't find anything with google, so I would need your help

I would like to cache my application, which contains a google maps iframe and a list of news, retrieved by RSS, to keep these informations for an offline use.

I read many tutorials about creation of a manifest and changing the .htaccess file, but in the case of my mobile application, I don't need any server so I don't have a .htaccess file.

So I thought about javascript localstorage, it's nice for my news but I don't see how to store my iframe with it, and anyway, is that just possible to store a google maps iframe to use it offline ?

Thank you !