By default all the apps (even compiled with Xcode 6 and iOS 8) will run in a scaled mode on both iPhone 6 & iPhone 6 plus.

Here is an example of how our app looked like in a scaled mode on iPhone 6.

For some reason, the only way to natively support iPhone 6 & iPhone 6 plus is to add a launch XIB file.

You use a launch XIB or storyboard file to indicate that your app runs on iPhone 6 Plus or iPhone 6. Launch Images

So after adding a launch XIB iOS 8 has finally recognized that our app is optimized for iPhone 6 & iPhone 6 plus. And it looks much better now!