Offline reading allows users to save content for when going offline - whether you're up in the air, camping in valleys, or traveling through the metro/tube where there's still no WiFi or signal.
Setting up offline reading
Navigate to the More tab at the bottom of the app, and you will see this screen:
Simply turn on "Offline Reading" using the switcher, and content will be stored for offline reading as you open sections of the app. This lets you focus on the content you want to save, since if you don't open a specific section, it will not be saved for offline. Moreover, however, if you do not open a section for a long time, the data saved for that section will be old.
Download Content Now method
When you want to get the freshest data for all the possible parts of the app that can be saved offline, you can press the Download Content Now button. This will refresh all the stored content across all parts. However, it only saves content when you press the button, so you can use this to refresh the whole app's cache just before you go offline so you have the latest content in all places.