I just checked one more time on the firewall and both answers are correct: Unused Apps and Without App Control. Both screens are similar and I could not see any difference in the format. However, the results outcome is different of course. so I am not quite sure which one should be correct in this case.

A little more on why it is Rules without Apps Control and not New App Viewer: Although both are true for this specific screenshot however the difference is that in New App Viewer, we get to see the rules which are configured with applications like web-browsing and such rules are not visible in Rules Without Apps Control. Thus, in New App Viewer, at times we get to see numbers under 'Apps Allowed' whereas on the other hand this column contains 'Any'. Moreover, the New Apps Allowed functionality requires PA Application Cloud Engine (ACE) SaaS subscription to get the App info from cloud DB. The Rules Without Apps Control is on-the-box functionality. Here's the definition from firewall's help page; New App Viewer—New cloud applications downloaded from the Application Control Engine if the firewall has a SaaS Security subscription. Rules Without App Controls—Rules that have the application set to any, so you can identify port-based rules to convert to application-based rules.