With the introduction of progressive web apps and browser APIs like persistent storage, payments, geolocation and push notifications, it's now possible to build full-featured mobile apps on the web platform. One important aspect of progressive web apps is the concept of building your app to be "offline-first." With an offline-first approach, you first design your app for the most resource-constrained environment. This approach provides a consistent user experience whether the user’s device has no connectivity, limited connectivity or great connectivity. One of the biggest benefits of offline-first apps is that they can be very fast, as they provide zero-latency access to content and data stored directly on the device.