Build mutliple Unity applications for multiple platforms with one click

BuildAutomation.cs

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;

public class BuildAutomation {
	public struct BuildTargetAndGroup {
		public BuildTargetGroup group;
		public BuildTarget target;
		public BuildTargetAndGroup (BuildTargetGroup group, BuildTarget target) {
			this.group = group;
			this.target = target;
		}
	}

	[MenuItem("My Project/Build/Build all")]
	public static void BuildAll () {
		string path = EditorUtility.SaveFolderPanel("Choose Location of Built Applications", "Builds", "");
		BuildApplication(path);
		BuildOtherApplication(path);
    	}
	public static void BuildApplication (string path) {
		string appName = "application";
		Texture2D icon = (Texture2D)AssetDatabase.LoadAssetAtPath("Assets/application.png", typeof(Texture2D));
		PlayerSettings.productName = "Application";
		PlayerSettings.applicationIdentifier = "com.myproject.application";
		PlayerSettings.defaultScreenWidth = 1024;
		PlayerSettings.defaultScreenHeight = 768;
		PlayerSettings.defaultIsFullScreen = true;
        	PlayerSettings.displayResolutionDialog = ResolutionDialogSetting.HiddenByDefault;
		//...

		BuildPlayerOptions buildPlayerOptions = new BuildPlayerOptions();
		buildPlayerOptions.scenes = new[] { "Assets/application.unity" };
		buildPlayerOptions.locationPathName = path;
		buildPlayerOptions.options = BuildOptions.None;

		BuildForTargetes(buildPlayerOptions, appName,  icon,
			new BuildTargetAndGroup(BuildTargetGroup.Standalone, BuildTarget.StandaloneOSX),
			new BuildTargetAndGroup(BuildTargetGroup.Standalone, BuildTarget.StandaloneWindows64),
			new BuildTargetAndGroup(BuildTargetGroup.Standalone, BuildTarget.StandaloneLinux64) );
	}

	public static void BuildOtherApplication (string path) {
		string appName = "otherApplication";
		Texture2D icon = (Texture2D)AssetDatabase.LoadAssetAtPath("Assets/otherApplication.png", typeof(Texture2D));
		PlayerSettings.productName = "Other Application";
		PlayerSettings.applicationIdentifier = "com.myproject.otherapplication";
		PlayerSettings.macFullscreenMode = MacFullscreenMode.FullscreenWindowWithDockAndMenuBar;
		PlayerSettings.defaultIsNativeResolution = false;
		PlayerSettings.defaultIsFullScreen = false;
		PlayerSettings.defaultScreenWidth = 400;
		PlayerSettings.defaultScreenHeight = 600;
		PlayerSettings.displayResolutionDialog = ResolutionDialogSetting.HiddenByDefault;
        	//...

		BuildPlayerOptions buildPlayerOptions = new BuildPlayerOptions();
		buildPlayerOptions.scenes = new[] { "Assets/otherApplication.unity" };
		buildPlayerOptions.locationPathName = path;
		buildPlayerOptions.options = BuildOptions.None;

		BuildForTargetes(buildPlayerOptions, appName, icon,
			new BuildTargetAndGroup(BuildTargetGroup.Standalone, BuildTarget.StandaloneOSX),
			new BuildTargetAndGroup(BuildTargetGroup.Standalone, BuildTarget.StandaloneWindows64),
			new BuildTargetAndGroup(BuildTargetGroup.Standalone, BuildTarget.StandaloneLinux64));
	}

	public static void BuildForTargetes(BuildPlayerOptions options, string appName, Texture2D icon, params BuildTargetAndGroup[] targets) {
		string locationPathName = options.locationPathName;
		foreach(BuildTargetAndGroup target in targets) {
			
			// https://forum.unity.com/threads/cant-change-resolution-for-standalone-build.323931/
			PlayerSettings.SetApplicationIdentifier(target.group, PlayerSettings.applicationIdentifier);
			DeletePreference();

			options.targetGroup = target.group;
			options.target = target.target;
			options.locationPathName = locationPathName + "/" + target.target.ToString() + "/" + appName;
			SetIconForTargetGroup(options.targetGroup, icon);
			//Debug.Log("building " + options.locationPathName);
			BuildPipeline.BuildPlayer(options);
		}
	}
	public static void SetIconForTargetGroup(BuildTargetGroup platform, Texture2D icon) {
		int[] iconSizes = PlayerSettings.GetIconSizesForTargetGroup(platform);
		Texture2D[] icons = new Texture2D[iconSizes.Length];
		for(int i=0; i<icons.Length; i++) {
			if(icon.width == iconSizes[i]) {
				icons[i] = icon;
			}
			else {
				Texture2D scaledIcon = new Texture2D(icon.width, icon.height, icon.format, false);
				Graphics.CopyTexture(icon, scaledIcon);
				scaledIcon.Resize(iconSizes[i], iconSizes[i], icon.format, false);
				scaledIcon.Apply();
				icons[i] = scaledIcon;
			}
		}
		PlayerSettings.SetIconsForTargetGroup(platform, icons);
	}
	public static void DeletePreference() {
		if(Application.platform == RuntimePlatform.OSXEditor || Application.platform == RuntimePlatform.OSXEditor){
			FileUtil.DeleteFileOrDirectory("~/Library/Preferences/"+PlayerSettings.applicationIdentifier+".plist");
		}
		else{
			Debug.LogWarning("Not sure how to delete Prefferences for this platform!");
			// https://forum.unity.com/threads/cant-change-resolution-for-standalone-build.323931/
		}
	}
}