I am not finding a straight forward site with the iOS8 sizes and names for the app icons and launch image.
I have seen the iOS Human Interface Guidelines but they don\'t
As rmaddy mentioned since Xcode 5 you don't need to name your icons in any specific way. Use the App Icon Asset
to add your icons.
Regarding the sizes for your icons, you'll also find them in your App Icon Asset Catalog, but for convenience here's a screenshot:
I also highly recommend using this icon template to create your icon because one: it provide an awesome psd file ready to edit and second: it provides actions to easily save every icon you need! Here it is: http://appicontemplate.com