I\'ve noticed running this would cause view (or main window, not sure) to resize for a moment, when running on iPhone 6/6+ simulator scaled from iPhone 5 layout (without passing
I just had this issue.
The reason was that I didn't have launch images suitable for iPhone 6 nor 6 plus. Another issue I saw because of this non-existing image was that I got size for iPhone 5 when I asked the screen size bounds like this:
CGSize screenSize = [[UIScreen mainScreen] bounds].size;
When I fixed these images, this issue was fixed.
P.S - it should work whether you use asset catalog or nib file for the launch image. In the asset catalog you should add the 'V' in right side (Attributes Inspector) under iOS 8 and later, and set images for 'Retina HD 5.5' (for 6 plus) and 'Retina HD 4.7' (for iPhone 6)