Actually, sites in Chrome can work fully offline today using Service Worker (http://www.html5rocks.com/en/tutorials/service-worker/introd...). And they can get users to add the site to their homescreen, so they have the full icon+offline experience (https://developers.google.com/web/updates/2015/03/increasing...).

Service Workers are also in Firefox Nightly right now, but are hidden behind an about:config flag until the feature is fully baked.

https://developer.mozilla.org/en-US/docs/Web/API/Service_Wor...

http://caniuse.com/serviceworkers

There's also the Application Cache, which has been fully supported in the stable versions for a while now.

https://developer.mozilla.org/en-US/docs/Web/HTML/Using_the_...

http://caniuse.com/offline-apps

And of course, FF for Android has an "Add to Homescreen" button too.

Application cache is a fucking nightmare. Service Worker's can't come soon enough.

Most apps are delivering content, so they also fail when offline.

Yes, there are a number of apps that cache some data locally, but I believe they're in the minority. Even casual games have to check in with a database and retrieve a couple datapoints about your progress, your in-app purchases, and what powerups are available to you.

On iPhone, this is what "reading list" is for.

All desktop browsers have a "save page" feature.

Surely the mobile browsers can do that too?

Chrome on iOS doesn't seem to be able to.