This article provides answers for InVision V6
Offline viewing is not available for V7 prototypes. To confirm your version, check the upper right corner of your dashboard.
When you use the InVision iOS App, you'll be able to load a prototype once, and it will remain available for offline viewing, unless you sign out of the app.
If you sign out, only the prototypes that were loaded via a share link will remain. Enabling airplane mode is recommended, as that will ensure we load from the offline version.
If you load a prototype from a share link, open it, and go offline, the prototype will remain, but you will see a warning message display that changes cannot be downloaded.