In addition to the user test mode on the InVision iOS app, you can get feedback on your InVision documents from real users by taking InVision share links to any other user testing service you currently rely on.
You'll need to generate a share link to use with your preferred testing service.
To hide the InVision logo and UI buttons while viewing a prototype via a share link, the viewer (or presenter) can use this keyboard shortcut: Command + Shift + .