Apple will label apps built for its new $1,999 foldable iPhone Duo

Apple is adding a "Made for iPhone Duo" badge to the App Store. It marks apps and games built to use the extra screen space on the new foldable. The iPhone Duo starts at $1,999 and launches Friday.

What the badge covers

The Duo has an inner screen and an outer screen. Apple showed how some well-known apps use them.

• Netflix fills the inner screen with shows and movies, and puts short clips on the outside.
• Prime Video can play with the Duo partly folded, with cast details below the video.
• Word puts formatting tools next to your document, and Outlook shows your inbox beside a full email.
• Zoom shows a video call next to shared content.

Apple also named Paramount Plus, NYT Cooking, Yelp, Lyft and United Airlines as optimized apps.

What to know before buying

The badge is not a promise that an app works well. The Verge's Nilay Patel found that some apps labeled as optimized, including Instagram, still had bugs.

Apple says it will launch editorial collections for the Duo on Friday, with more app updates through the year. Stock is limited and sold on a walk-in basis. Apple did not show what the badge looks like, and it has not said which apps are still to come.