Exact size of image for icon and splash screen

Originally from ticket #846. my PNGs look blurry as I'm sure the UI is stretching/maximizing what I feed it. What are the proper icon sizes for the icon and the splash screen, so it will look sharp? Is this for the app icon or splash screen, or both? Both. For the icon, the best size to give the page is 144x144. For the splash screen, the best size 1536 wide by 2048 high.