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
You can use any name for icons as there is no requirement for any specific name. To get icons with proper sizes you can use following shell script to generate them without any additional tools:
FILE="largeicon.png" # iTunes Artwork sips --resampleWidth 1024 "${FILE}" --out "iTunesArtwork@2x.png" sips --resampleWidth 512 "${FILE}" --out "iTunesArtwork.png" # iPhone iOS 7, 8 sips --resampleWidth 58 "${FILE}" --out "icon-iphone-29@2x.png" sips --resampleWidth 87 "${FILE}" --out "icon-iphone-29@3x.png" sips --resampleWidth 80 "${FILE}" --out "icon-iphone-40@2x.png" sips --resampleWidth 120 "${FILE}" --out "icon-iphone-40@3x.png" sips --resampleWidth 120 "${FILE}" --out "icon-iphone-60@2x.png" sips --resampleWidth 180 "${FILE}" --out "icon-iphone-60@3x.png" # iPad iOS 7, 8 sips --resampleWidth 29 "${FILE}" --out "icon-ipad-29.png" sips --resampleWidth 58 "${FILE}" --out "icon-ipad-29@2x.png" sips --resampleWidth 40 "${FILE}" --out "icon-ipad-40.png" sips --resampleWidth 80 "${FILE}" --out "icon-ipad-40@2x.png" sips --resampleWidth 76 "${FILE}" --out "icon-ipad-76.png" sips --resampleWidth 152 "${FILE}" --out "icon-ipad-76@2x.png" # Apple Watch sips --resampleWidth 48 "${FILE}" --out "icon-watch-24@2x.png" sips --resampleWidth 55 "${FILE}" --out "icon-watch-27p5@2x.png" sips --resampleWidth 58 "${FILE}" --out "icon-watch-29@2x.png" sips --resampleWidth 87 "${FILE}" --out "icon-watch-29@3x.png" sips --resampleWidth 80 "${FILE}" --out "icon-watch-40@2x.png" sips --resampleWidth 88 "${FILE}" --out "icon-watch-44@2x.png" sips --resampleWidth 172 "${FILE}" --out "icon-watch-86@2x.png" sips --resampleWidth 196 "${FILE}" --out "icon-watch-98@2x.png"