This script makes app icons by resizing copies of a source image for all required App Store sizes (currently Message Application icon sizes only).
This script requires installing the ImageMagick CLI.
You can get it here: http://www.imagemagick.org/
The script will check for ImageMagick before running.
resize-app-icon.sh
// This script/resized
// Output destination for the script
The script takes a single argument: the source png
image to create the resized files from.
Usage:
bash ./resize-app-icon.sh app-icon.png