App Icon generator script, based on: https://gist.github.com/donnywals/3be3774435cf53133ee7f8c553e9c080

app_icon.sh

#!/bin/sh

# Takes filename as parameter.
file=$1

if [ -z "$file" ]
then
  echo "<png_file> argument not specified."
  exit 1
elif [ ! -f "$file" ]
then
  echo "$file was not found."
  exit 1
fi

iconSet="AppIcon.appiconset"

rm -rf $iconSet
mkdir -p $iconSet

# Icon 20
convert $file -resize 20x20 $iconSet/icon-20@1x.png
convert $file -resize 40x40 $iconSet/icon-20@2x.png
convert $file -resize 60x60 $iconSet/icon-20@3x.png

# Icon 29
convert $file -resize 29x29 $iconSet/icon-29@1x.png
convert $file -resize 58x58 $iconSet/icon-29@2x.png
convert $file -resize 87x87 $iconSet/icon-29@3x.png

# Icon 40
convert $file -resize 40x40 $iconSet/icon-40@1x.png
convert $file -resize 80x80 $iconSet/icon-40@2x.png
convert $file -resize 120x120 $iconSet/icon-40@3x.png

# Icon 50
convert $file -resize 50x50 $iconSet/icon-50@1x.png
convert $file -resize 100x100 $iconSet/icon-50@2x.png

# Icon 57
convert $file -resize 57x57 $iconSet/icon-57@1x.png
convert $file -resize 114x114 $iconSet/icon-57@2x.png

# Icon 60
convert $file -resize 120x120 $iconSet/icon-60@2x.png
convert $file -resize 180x180 $iconSet/icon-60@3x.png

# Icon 72
convert $file -resize 72x72 $iconSet/icon-72@1x.png
convert $file -resize 144x144 $iconSet/icon-72@2x.png

# Icon 76
convert $file -resize 76x76 $iconSet/icon-76@1x.png
convert $file -resize 152x152 $iconSet/icon-76@2x.png

# Icon 83.5
convert $file -resize 167x167 $iconSet/icon-83_5@2x.png

# Icon marketing
cp $file $iconSet/ios-marketing.png



json='{ "info" : { "version" : 1, "author" : "xcode" }, "images" : [ { "size" : "40x40", "idiom" : "ipad", "filename" : "icon-40@1x.png", "scale" : "1x" }, { "size" : "40x40", "idiom" : "ipad", "filename" : "icon-40@2x.png", "scale" : "2x" }, { "size" : "60x60", "idiom" : "iphone", "filename" : "icon-60@2x.png", "scale" : "2x" }, { "size" : "72x72", "idiom" : "ipad", "filename" : "icon-72@1x.png", "scale" : "1x" }, { "size" : "72x72", "idiom" : "ipad", "filename" : "icon-72@2x.png", "scale" : "2x" }, { "size" : "76x76", "idiom" : "ipad", "filename" : "icon-76@1x.png", "scale" : "1x" }, { "size" : "76x76", "idiom" : "ipad", "filename" : "icon-76@2x.png", "scale" : "2x" }, { "size" : "50x50", "idiom" : "ipad", "filename" : "icon-50@1x.png", "scale" : "1x" }, { "size" : "50x50", "idiom" : "ipad", "filename" : "icon-50@2x.png", "scale" : "2x" }, { "size" : "29x29", "idiom" : "iphone", "filename" : "icon-29@1x.png", "scale" : "1x" }, { "size" : "29x29", "idiom" : "iphone", "filename" : "icon-29@2x.png", "scale" : "2x" }, { "size" : "57x57", "idiom" : "iphone", "filename" : "icon-57@1x.png", "scale" : "1x" }, { "size" : "57x57", "idiom" : "iphone", "filename" : "icon-57@2x.png", "scale" : "2x" }, { "size" : "29x29", "idiom" : "iphone", "filename" : "icon-29@3x.png", "scale" : "3x" }, { "size" : "40x40", "idiom" : "iphone", "filename" : "icon-40@3x.png", "scale" : "3x" }, { "size" : "60x60", "idiom" : "iphone", "filename" : "icon-60@3x.png", "scale" : "3x" }, { "size" : "40x40", "idiom" : "iphone", "filename" : "icon-40@2x.png", "scale" : "2x" }, { "size" : "29x29", "idiom" : "ipad", "filename" : "icon-29@1x.png", "scale" : "1x" }, { "size" : "29x29", "idiom" : "ipad", "filename" : "icon-29@2x.png", "scale" : "2x" }, { "size" : "83.5x83.5", "idiom" : "ipad", "filename" : "icon-83_5@2x.png", "scale" : "2x" }, { "size" : "20x20", "idiom" : "iphone", "filename" : "icon-20@2x.png", "scale" : "2x" }, { "size" : "20x20", "idiom" : "iphone", "filename" : "icon-20@3x.png", "scale" : "3x" }, { "size" : "20x20", "idiom" : "ipad", "filename" : "icon-20@1x.png", "scale" : "1x" }, { "size" : "20x20", "idiom" : "ipad", "filename" : "icon-20@2x.png", "scale" : "2x" }, { "size" : "1024x1024", "idiom" : "ios-marketing", "filename" : "ios-marketing.png", "scale" : "1x" } ] }'
echo $json > $iconSet/Contents.json