More than 100,000 apps are optimized for the iPhone Duo, by the Apple figure MacRumors cites, and the hard part is finding the ones built around the fold. The video's ten picks, chosen two weeks into living with the phone, lean on the Duo's poses as much as its inner screen, and two of them, Delta and MD Vinyl, also made the earlier iPhone Duo apps that use the hinge list.

Open flat, like a small iPad

  • Fantastical. A full week spreads across the inner display, the kind of view MacRumors says makes the case for the bigger screen.
  • Bear. Apple named it as a notes app that uses the inner display, and the video likens writing in it to using an iPad.
  • CalibReader. An EPUB and PDF reader with a two-page spread and page-turn animations. Closed, the cover screen shows the cover of the book.

Half folded, like a laptop

  • Delta. It lays DS-style controls across both halves, and closing the Duo puts the game to sleep, like shutting the real handheld. It runs other classic systems too.
  • Battlefleet Duo. Battleship rules, with your fleet on the lower half and the enemy's water on the upper.
  • BrainDrain. A 60-second brain dump that changes input with the pose: typing in laptop mode, typing on the cover screen when closed, voice capture in tent mode.

Standing up, or closed on cue

  • MD Vinyl. A record spins under the album art, and in tent mode the cover screen shows both. It plays from Apple Music or Spotify.
  • Blankie. Soundscapes for focus or sleep, with Now Playing on one half and the rain and wind mixer on the other. In tent mode it's a small white noise machine.
  • VNTG. An instant camera: close the Duo to take the photo, then open it to develop the shot.
  • Who's at the Door? The phone becomes a door. Something knocks, you open it, and if what's there is scary, you slam it shut fast. MacRumors isn't sure what repeated slams do to the hinge and suggests keeping sessions short.

Fantastical and Bear would work on any big screen. The other eight need the hinge, and those are where I'd point any iPhoner new to the Duo, VNTG first.