localForage
Offline storage using a simple but powerful API
...It allows developers to store many types of data instead of just strings. localForage includes a localStorage-backed fallback store for browsers with no IndexedDB or WebSQL support. Asynchronous storage is available in the current versions of all major browsers: Chrome, Firefox, IE, and Safari (including Safari Mobile). localForage offers a callback API as well as support for the ES6 Promises API, so you can use whichever you prefer.