Hi David. This is a little late I realize, but I have found that this solution worked with Xcode 8 and does not require Xcode 9.
Add a UILaunchImages key to the info.plist.
Mine is pasted below, which supports iPad (9.7, 10.5, 12.9 inches) and iPhone (3.5, 4, 4.7, 5.8 inches).
In the UILaunchImageSize key, make sure the comma has a trailing space.
Both Landscape and Portrait UILaunchImageSize dicts should include the same portrait dimensions (don't reverse width and height).
The LaunchImage PNG files should be at the root level of your app's project, and their filename roots should not include @2x or @3x suffixes, but be a those retina resolutions. Example: LaunchImage-iPad10_5-Port should be 1668 x 2224.
The LaunchImageName keys should not include filename extensions.
And, of course, be sure to add those LaunchImage PNGs to your Project.
On the Project's General tab:
The Requires Full Screen checkbox is unchecked.
Launch Images Source is not set.
Launch Screen File is blank.
Hope this helps! It helped my app launch on a iPad Pro 10.5-inch in full native resolution. I have tested this on both iOS 10 and 11.
<key>UILaunchImages</key>
<array>
<dict>
<key>UILaunchImageMinimumOSVersion</key>
<string>7.0</string>
<key>UILaunchImageName</key>
<string>LaunchImage-iPad12_9-Port</string>
<key>UILaunchImageOrientation</key>
<string>Portrait</string>
<key>UILaunchImageSize</key>
<string>{1024, 1366}</string>
</dict>
<dict>
<key>UILaunchImageMinimumOSVersion</key>
<string>7.0</string>
<key>UILaunchImageName</key>
<string>LaunchImage-iPad12_9-Land</string>
<key>UILaunchImageOrientation</key>
<string>Landscape</string>
<key>UILaunchImageSize</key>
<string>{1024, 1366}</string>
</dict>
<dict>
<key>UILaunchImageMinimumOSVersion</key>
<string>7.0</string>
<key>UILaunchImageName</key>
<string>LaunchImage-iPad10_5-Port</string>
<key>UILaunchImageOrientation</key>
<string>Portrait</string>
<key>UILaunchImageSize</key>
<string>{834, 1112}</string>
</dict>
<dict>
<key>UILaunchImageMinimumOSVersion</key>
<string>7.0</string>
<key>UILaunchImageName</key>
<string>LaunchImage-iPad10_5-Land</string>
<key>UILaunchImageOrientation</key>
<string>Landscape</string>
<key>UILaunchImageSize</key>
<string>{834, 1112}</string>
</dict>
<dict>
<key>UILaunchImageMinimumOSVersion</key>
<string>7.0</string>
<key>UILaunchImageName</key>
<string>LaunchImage-iPad9_7-Port</string>
<key>UILaunchImageOrientation</key>
<string>Portrait</string>
<key>UILaunchImageSize</key>
<string>{768, 1024}</string>
</dict>
<dict>
<key>UILaunchImageMinimumOSVersion</key>
<string>7.0</string>
<key>UILaunchImageName</key>
<string>LaunchImage-iPad9_7-Land</string>
<key>UILaunchImageOrientation</key>
<string>Landscape</string>
<key>UILaunchImageSize</key>
<string>{768, 1024}</string>
</dict>
<dict>
<key>UILaunchImageMinimumOSVersion</key>
<string>7.0</string>
<key>UILaunchImageName</key>
<string>LaunchImage-iPhone5_5-Port</string>
<key>UILaunchImageOrientation</key>
<string>Portrait</string>
<key>UILaunchImageSize</key>
<string>{414, 736}</string>
</dict>
<dict>
<key>UILaunchImageMinimumOSVersion</key>
<string>7.0</string>
<key>UILaunchImageName</key>
<string>LaunchImage-iPhone5_5-Land</string>
<key>UILaunchImageOrientation</key>
<string>Landscape</string>
<key>UILaunchImageSize</key>
<string>{414, 736}</string>
</dict>
<dict>
<key>UILaunchImageMinimumOSVersion</key>
<string>7.0</string>
<key>UILaunchImageName</key>
<string>LaunchImage-iPhone4_7-Port</string>
<key>UILaunchImageOrientation</key>
<string>Portrait</string>
<key>UILaunchImageSize</key>
<string>{375, 667}</string>
</dict>
<dict>
<key>UILaunchImageMinimumOSVersion</key>
<string>7.0</string>
<key>UILaunchImageName</key>
<string>LaunchImage-iPhone4_0-Port</string>
<key>UILaunchImageOrientation</key>
<string>Portrait</string>
<key>UILaunchImageSize</key>
<string>{320, 568}</string>
</dict>
<dict>
<key>UILaunchImageMinimumOSVersion</key>
<string>7.0</string>
<key>UILaunchImageName</key>
<string>LaunchImage-iPhone3_5-Port</string>
<key>UILaunchImageOrientation</key>
<string>Portrait</string>
<key>UILaunchImageSize</key>
<string>{320, 480}</string>
</dict>
</array>