When iPhone 6 came out, the non-updated apps in app store were stretched/scaled up with same aspect ratio.
How will the current apps in the app store scale on iPhone X? I.e. without rebuilding them with SDK 11 / Xcode9.
The only realistic option I can think about for iPhone X is that the full screen will not be used? I.e. same aspect ratio as the iPhone 6 & 7.
What makes me think that it will be some kind of "shrinked area" for the iPhone X+SDK10 is that almost ALL apps in the appstore will be broken for iPhone X unless the apps get updated within a month. In reality – This will not happen. Alot of apps will not be updated at the date of iPhone X release.
EDIT:
To clarify, I don't ask for how the apps will look when rebuilt with xcode9/SDK11. I want to know how the apps behave without rebuilding them!
Best Answer
Right now most of the apps are made with Auto Layout, so they are not going to be "scaled" but rather position of the items may be different. The biggest problem is to handle the top area of the display. I checked some of the apps in the iPhoneX Simulator and apps that display status bar do not have any problems. With status bar hidden and without navigation bar there could be problems. Here's the Hero Sample app from YiLun Zhao :
As you can see, Tab bar is "stretched" downward, but top scrolled area is displayed rather strange. For example section separators are displayed under the "status area" (bottom of it), but table content is clearly visible underneath (side by side with black camera area).
I checked some other apps and there are no major problems with the UI.
So the answer to your question is - it depends how developers made their apps. If they've used Auto Layout there shouldn't be a problem.
P.S. even though the display is bigger than iPhones Plus it has "compact" horizontal traits in landscape -> there won't be split view. Also pages loaded in the landscape view do not occupy the whole screen width (there are white stripes on the both sides. Screenshot:
NOTE: This is still Xcode Beta, so maybe things will change when iPhone X is released.