UpUp

UpUp is a tiny JavaScript library that makes sure your users can always access your site's content, even when they're on a plane, in an elevator, or 20,000 leagues under the sea. Your users are no longer sitting at their desktops, with a wire connecting them to the internet. They are visiting your site from a phone in an elevator, from their tablet on the subway, or on their laptop while they sit cramped into seat 25 E. This is why modern browsers support service workers, a new technology which lets you serve your content to your users, even when they are offline. UpUp is a free, open-source project which makes using this modern magic as simple as calling one command. While easy to pick up, UpUp is powerful enough to support anything from showing simple messages, to making fully functional single-page applications available offline, with data customized for each of your users.