One complexity that seems to show up in articles about this is that:


  Note that the MIME type of the manifest file is text/cache-manifest.


And the examples all seem to list specific files to cache (but I may need to read further).

Offline tiled map web app
In our app, when you save/submit a form, two things happen


submit button greys out(becomes disabled)
there's a progress bar running at the top of the page(similar to medium.com), which is an indicator used across the app for an ongoing action(not limited only to saving forms, since it's an SPA app)


Do you think it's clear enough for the user that things are being saved, or it would be better to add a loader directly associated with the form(inside the button for example)?

Here's what it looks like at the moment.
https://youtu.be/xzc7P8R751M
