Fastlane actions mentioned in the Kunstmaan Labs blogpost "iOS continuous delivery with Jenkins and Fastlane" found at https://labs.kunstmaan.be/blog/ios-continuous-delivery-with-jenkins-and-fastlane

app_name.rb

module Fastlane
  module Actions
    class AppNameAction < Action
      def self.run(params)
        require 'plist'
        identifier_key = 'CFBundleDisplayName'
        folder = Dir['*.xcodeproj'].first
        info_plist_path = params[:plist_path]
        raise "Couldn't find info plist file at path '#{params[:plist_path]}'".red unless File.exist?(info_plist_path)
        plist = Plist.parse_xml(info_plist_path)
        plist[identifier_key] = params[:app_name]
        plist_string = Plist::Emit.dump(plist)
        File.write(info_plist_path, plist_string)
        Helper.log.info "Updated #{params[:plist_path]} 💾.".green
      end

      #####################################################
      # @!group Documentation
      #####################################################

      def self.is_supported?(platform)
        [:ios].include?(platform)
      end

      def self.description
        'Update an app name'
      end

      def self.available_options
        [
          FastlaneCore::ConfigItem.new(key: :plist_path,
                                       env_name: "FL_UPDATE_APP_IDENTIFIER_PLIST_PATH",
                                       description: "Path to info plist, relative to your Xcode project",
                                       verify_block: proc do |value|
                                         raise "Invalid plist file".red unless value[-6..-1].downcase == ".plist"
                                       end),
          FastlaneCore::ConfigItem.new(key: :app_name,
                                       env_name: 'FL_UPDATE_APP_NAME',
                                       description: 'The app name of your app',
                                       verify_block: proc do |value|
                                          raise "No app_name".red unless (value and not value.empty?)
                                       end)
        ]
      end

      def self.authors
        ['@r0derik']
      end
    end
  end
end

build_number_icon.rb

# Based on: https://gist.github.com/rgm/5377144
# Requires ImageMagick: `brew install imagemagick ghostscript`

module Fastlane
  module Actions

    class NoSourceFileError < ArgumentError; end

    class Icon
      attr_accessor :src, :dst
      def src= path
        if File.exist? path
          @src = path
        else
          raise NoSourceFileError, "no icon file at #{path}"
        end
      end
      def stamp_icon_with str
        `convert -background '#0008' -fill white -font Helvetica -density 300 -gravity Center -size #{banner_dims} caption:"#{str}" "#{@src}" +swap -gravity South -composite "#{@dst}"`
      end
      def banner_dims
        banner_ht = (dims[:ht] * 0.2).floor
        "#{dims[:wd]}x#{banner_ht}" # imagemagick-style format string
      end
      def dims
        return @dims if @dims
        data = `identify -format "%w %h" "#{@src}"`.strip.split.map(&:to_i)
        @dims = {:wd => data[0], :ht => data[1]}
      end
    end

    class BuildNumberIconAction < Action
      def self.run(params)
        icons = sh("find . -iname 'Icon-*'")
        icons.each_line do |stem|
          begin
            source = stem.strip
            i = Icon.new
            i.src = source
            i.dst = "#{source}-edit"
            version = ENV["BUILD_NUMBER"] || "1234"
            i.stamp_icon_with "##{version}"
            FileUtils.cp i.dst, i.src
            FileUtils.rm i.dst
          rescue NoSourceFileError => msg
            STDERR.puts "Warning: #{msg}"
          end
        end
      end

      #####################################################
      # @!group Documentation
      #####################################################

      def self.description
        "Adds the build number to the Icons"
      end

      def self.authors
        ["@r0derik"]
      end

      def self.is_supported?(platform)
        platform == :ios
      end
    end
  end
end

color_icon.rb

# Based on: https://gist.github.com/rgm/5377144
# Requires ImageMagick: `brew install imagemagick ghostscript`

module Fastlane
  module Actions

    class NoSourceFileError < ArgumentError; end

    class Icon
      attr_accessor :src, :dst
      def src= path
        if File.exist? path
          @src = path
        else
          raise NoSourceFileError, "no icon file at #{path}"
        end
      end
      def color_icon modulation
        #{}`convert "#{@src}" -fuzz 25% -fill '#{to}' -opaque '#{from}' "#{@dst}"`
        `convert "#{@src}" -modulate 100,100,#{modulation} "#{@dst}"`
      end
    end

    class ColorIconAction < Action
      def self.run(params)
        icons = sh("find . -iname 'Icon-*'")
        icons.each_line do |stem|
          begin
            source = stem.strip
            i = Icon.new
            i.src = source
            i.dst = "#{source}-edit"
            i.color_icon "#{params[:modulation]}"
            FileUtils.cp i.dst, i.src
            FileUtils.rm i.dst
          rescue NoSourceFileError => msg
            STDERR.puts "Warning: #{msg}"
          end
        end
      end

      #####################################################
      # @!group Documentation
      #####################################################

      def self.description
        "Changes the color of all Icon* files with a modulation degree"
      end

      def self.available_options
        [
          FastlaneCore::ConfigItem.new(key: :modulation,
                                       env_name: "COLOR_MODULATION",
                                       description: "Modulation degrees",
                                       verify_block: proc do |value|
                                          raise "No from color `modulation: '33.3'`".red unless (value and not value.empty?)
                                       end)
        ]
      end

      def self.authors
        ["@r0derik"]
      end

      def self.is_supported?(platform)
        platform == :ios
      end
    end
  end
end