Unity3D Editor Utility to install a built apk to multiple android devices.

InstallToAllAndroidDevices.cs

using UnityEngine;
using UnityEditor;
using UnityEditor.Callbacks;
using System.IO;
using System.Diagnostics;
using System.Collections.Generic;
using System.Threading;

using Debug = UnityEngine.Debug;

/// <summary>
/// Automates installation to all USB connected Android devices.
/// Some devices do not properly report success.
/// Needs to be made async so that progress can be reported.
/// 
/// Set AUTORUN = false to only allow use via the Editor menu.
/// 
/// </summary>
#pragma warning disable 0162
public class InstallToAllAndroidDevices : EditorWindow
{
	private const string ANDROID_SDK_PATH_PREF_KEY = "AndroidSdkRoot";

	private const string LAST_APK_PATH_PREF_KEY = "LastApkBuildPath-InstallToAll";

	private const bool AUTORUN = false;

	[PostProcessBuild]
	public static void OnPostprocessBuild(BuildTarget target, string pathToBuiltProject)
	{
		if (target != BuildTarget.Android)
			return;

		EditorPrefs.SetString(LAST_APK_PATH_PREF_KEY, pathToBuiltProject);

		if (AUTORUN)
			InstallToAll(pathToBuiltProject);
	}

	[MenuItem("Edit/Install last APK to all")]
	public static void RunIt()
	{
		InstallToAll(EditorPrefs.GetString(LAST_APK_PATH_PREF_KEY, ""));
	}

	private static bool running = false;
	private static bool started = false;

	private static void InstallToAll(string apkPath)
	{
		string title = "Installing to connected devices";
		
		started = true;
		EditorUtility.ClearProgressBar();
		EditorApplication.update += OnGUI;

		EditorUtility.DisplayProgressBar(title, apkPath, 0);
		Debug.LogFormat("Installing '{0}' to all connected Android devices.", apkPath);

		List<string> devices = GetAdbDevices();

		if (devices.Count <= 0)
		{
			Debug.LogError("No Android devices found");
			return;
		}

		string adbPath = GetAdbPath();

		if (string.IsNullOrEmpty(adbPath))
			return;

		if (!File.Exists(apkPath))
		{
			Debug.LogErrorFormat("Could not find APK file at: '{0}'", apkPath);
			return;
		}

		running = true;

		for (int i = 0; i < devices.Count; i++)
		{
			Process adbProcess = new Process();
			adbProcess.StartInfo.UseShellExecute = false;
			adbProcess.StartInfo.RedirectStandardOutput = true;
			adbProcess.StartInfo.RedirectStandardError = true;
			adbProcess.StartInfo.CreateNoWindow = true;
			adbProcess.StartInfo.FileName = adbPath;
			adbProcess.EnableRaisingEvents = true;


			List<string> errors = new List<string>();
			adbProcess.ErrorDataReceived += (sender, args) =>
			{
				errors.Add(args.Data);
			};

			Debug.Log("Installing to device: " + devices[i]);
			adbProcess.StartInfo.Arguments = "-s " + devices[i] + " install -r \""+ apkPath + "\"";

			EditorUtility.DisplayProgressBar(title, devices[i], (i + 1f) / (devices.Count + 1f));

			adbProcess.Exited += (o, e) =>
			{
				List<string> output = new List<string>();
				string line = "";
				while ((line = adbProcess.StandardOutput.ReadLine()) != null)
				{
					if (line.Length > 0 && line[0] != '[')
						output.Add(line);
				}

				//adbProcess.WaitForExit();

				if (output.Count > 0 && output[output.Count - 1].ToLower() == "success")
					Debug.Log("Success!");
				else
				{
					var sb = new System.Text.StringBuilder();
					sb.AppendLine("Failure! Error count: " + errors.Count);
					foreach (var item in errors)
					{
						sb.AppendLine(item);
					}
					errors.Clear();

					sb.AppendLine("Output:");
					foreach (var item in output)
					{
						sb.AppendLine(item);
					}

					Debug.LogWarning(sb);
				}

				if (i >= devices.Count - 1)
				{
					running = false;
				}

			};
			adbProcess.Start();
			//adbProcess.WaitForExit();
		}
		
	}

	private static List<string> GetAdbDevices()
	{
		List<string> devices = new List<string>();
		
		string adbPath = GetAdbPath();

		if (string.IsNullOrEmpty(adbPath))
			return devices;

		Process adbProcess = new Process();
		adbProcess.StartInfo.UseShellExecute = false;
		adbProcess.StartInfo.RedirectStandardOutput = true;
		adbProcess.StartInfo.CreateNoWindow = true;
		adbProcess.StartInfo.FileName = adbPath;
		adbProcess.StartInfo.Arguments = "devices";
		adbProcess.Start();
		
		string line;
		while ((line = adbProcess.StandardOutput.ReadLine()) != null)
		{
			string[] split = line.Split('\t');

			if (split.Length > 1)
			{
				devices.Add(split[0]);
			}
		}

		adbProcess.WaitForExit();

		return devices;
	}

	private static string GetAdbPath()
	{
		if (!EditorPrefs.HasKey(ANDROID_SDK_PATH_PREF_KEY))
		{
			Debug.LogError("Please ensure that the Android SDK path is specified in the editor prefs");
			return null;
		}

		string adbPath = Path.Combine(
			EditorPrefs.GetString(ANDROID_SDK_PATH_PREF_KEY),
			"platform-tools/adb.exe");

		if (!File.Exists(adbPath))
		{
			Debug.LogErrorFormat("Could not find ADB.EXE at the expected path: '{0}'", adbPath);
			return null;
		}

		return adbPath;
	}

	private static void OnGUI()
	{
		if (started && !running)
		{
			started = false;
			EditorUtility.ClearProgressBar();
			EditorApplication.update -= OnGUI;
		}
	}
}

Needs to be made asynchronous so that progress can be reported.

Made asynchronous with progress bar.