Launch Image Generator Xcode. This is a very frustrating part of xcode. Iconizer will create an image set that you can use directly within xcode.
Just drag and drop an image and then all size icons for xcode will be ready. Generate image sets one image to generate 1x 2x and 3x scaled images create just one image at the scale of 3x drop it onto iconizer choose a truly awesome name and export it. Assetsgenerator will export the sizes according to the settings of xcode project target.
App icon maker will generate all required app icon sizes for ios and android projects.
With app icon maker you can import app icons to xcode android studio and visual studio. You could generate all icons from a single 2048x2048 png. Compatible with ios11 and android. App icon maker will generate all required app icon sizes for ios and android projects.