Prerequisite knowledge
Prior experience developing iOS apps with Adobe AIR will help you make the most of this article.
Required products
Adobe AIR
User level

According to the Apple iOS human interface guidelines, developers must provide at least one launch image for an iOS app.  For an enhanced user experience, however, Apple expects apps to have launch images for all supported devices and resolutions. 
This article covers the use of launch images with Adobe AIR applications on iOS.

Launch image basics

In general, an iPhone application should have a portrait launch image, and an iPad application should have a launch image for both possible launch orientations of the application. As noted in Apple’s Custom Icon and Image Creation Guidelines, every application should include launch images for different sizes and resolutions. If you look at the sizes closely, you’ll notice that Apple expects full-screen launch images for iPhone, but non-full-screen launch images for iPad. This size recommendation does not depend on the app.
A launch image must be visible instantly when the user starts the application and must remain visible until the application is fully ready to use. For AIR applications, this means the launch image must remain visible until the AIR runtime is completed initialized. To achieve this, the AIR runtime displays the same launch image as shown by iOS until the app is completely ready to use. Recently, there were some instances in which launch images appeared to drift slightly during application launch. This occurred because Apple expected full-screen launch images for iPhone but not for iPad. The drift was due to image scaling when a full-screen launch image was displayed in a non-full-screen area (on iPhone) or a non-full-screen launch image in a full-screen area (on iPad).
To resolve these issues permanently, Adobe changed the guidelines for launch screen image sizes for iPad in AIR 3.4. In the new guidelines, all AIR applications for the iOS platform are expected to include only the full-screen launch images at the resolution of the supported device. This means that the expected image size of the default portrait image for a high resolution iPad would be 1536 × 2048 for AIR 3.4 onwards. This is true for full-screen and non-full-screen apps. The extra 40 pixels are hidden behind the status bar for non-full-screen apps.
Table 1 shows the expected launch image sizes for AIR applications on the iOS platform for AIR 3.4 and later.
Table 1. Launch image sizes for iOS devices.
Portrait size Landscape size
12.9" iPad Pro
2048px × 2732px 2732px × 2048px
11" iPad Pro 1668px × 2388px 2388px × 1668px
10.5" iPad Pro 1668px × 2224px 2224px × 1668px
9.7" iPad 1536px × 2048px 2048px × 1536px
7.9" iPad mini 4 1536px × 2048px 2048px × 1536px
iPhone XS Max 1242px × 2688px 2688px × 1242px
iPhone XS 1125px × 2436px 2436px × 1125px
iPhone XR 828px × 1792px 1792px × 828px
iPhone X 1125px × 2436px 2436px × 1125px
iPhone 8 Plus 1242px × 2208px 2208px × 1242px
iPhone 8 750px × 1334px 1334px × 750px
iPhone 7 Plus 1242px × 2208px 2208px × 1242px
iPhone 7 750px × 1334px 1334px × 750px
iPhone 6s Plus 1242px × 2208px 2208px × 1242px
iPhone SE 640px × 1136px 1136px × 640px

Naming conventions

For details on the file naming scheme used for launch images, see the iOS Launch Images section in Building Adobe AIR Applications.
For iPhone 5 append -568h to the launch image file name. For example, the default file would be Default-568h@2x.png. (The @2x is included for launch images intended for high-resolution retina displays). Non-retina mode is also supported on the iPhone 5. However, launch images should be packaged for the device, so even if you run an app in non-retina mode it is better to package the Default-568h@2x.png file and then use the non-retina resolution in the app.

Where to go from here

Here are some resources on iOS launch images: