Offline App - zip - json - webserver

I have an app that must be extend with the following functionality: - App is installed by the user. - First time the app is installed there should be a check to a web server to see what design should be downloaded. Based on the number (1,2,3,4...) the correct styling ZIP ([login to view URL], [login to view URL], etc.) should be downloaded and unpacked for the app. Because this styline zip also include some JSON files + HTML the app design should now work offline too. - User can now open the app and run the complete app offline. - Also there should be a check each hour to another web server to see if there are updated. If there is an update the app should download the JSON files + images so this is all working offline too. This solution should be build for Android and iOs.