First load, service workers are installed.
Second load, it is cached for offline viewing.

Available Offline

After second page load, This content is available offline

Available Offline

After second page load, This content is available offline

Available Offline

After second page load, This content is available offline

Available Offline

After second page load, This content is available offline

Available Offline

After second page load, This content is available offline

Available Offline

After second page load, This content is available offline

Available Offline

After second page load, This content is available offline

Available Offline

After second page load, This content is available offline