The popular retro game emulator Delta has today launched a big new 2.0 version, most notably featuring a refreshed Liquid Glass interface and support for the iPhone Duo.

The app now has specially-designed controller skins that are optimized for all the different iPhone Duo poses, including some beautiful Nintendo DS layouts that use the full size of the inner display, and cleverly spans the crease when partially folded in book mode in portrait.

The bigger screen of the iPhone Duo enables some immersive gaming experiences, but the Delta developers have also ensured that the app naturally reflows on the portrait closed outer screen too.

Another little easter egg is that you can fold the Duo closed to automatically put the DS to sleep, emulating the physical behavior of a real DS console.

Delta also has a special trick when using it in landscape split view alongside another app.…