PlayModeView wrapper for Unity that describes which type of Play Mode is currently active on the screen. Useful to determine between GameView and DeviceSimulator.

PlayModeView.cs

#if UNITY_EDITOR
using System;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using UnityEditor;
using UnityEngine;

[InitializeOnLoad]
public static class PlayModeView
{
    public enum Type
    {
        Unknown,
        Game,
        DeviceSimulator
    }

    private static readonly Version _version;
    private static readonly bool _packageFound;

    static PlayModeView()
    {
        _packageFound = TryGetPackageVersion(out _version);
    }

    public static Type GetCurrentViewType()
    {
        if (!_packageFound)
            return Type.Game;
        
        var editorAssembly = typeof(EditorWindow).Assembly;
        var simulatorAssembly = AppDomain.CurrentDomain.GetAssemblies()
            .FirstOrDefault(i => i.GetName().Name == "Unity.DeviceSimulator.Editor");

        var gameViewType = editorAssembly.GetType("UnityEditor.GameView");
        var simulatorWindowType = simulatorAssembly?.GetType(GetSimulatorWindowType());
        var gameViewWindow = Resources.FindObjectsOfTypeAll(gameViewType);
        var simulatorViewWindow = simulatorAssembly != null ? Resources.FindObjectsOfTypeAll(simulatorWindowType) : null;
        
        if (gameViewWindow.Length > 0)
            return Type.Game;
        if (simulatorViewWindow != null && simulatorViewWindow.Length > 0)
            return Type.DeviceSimulator;

        return Type.Unknown;
    }

    private static string GetSimulatorWindowType()
    {
        if (!_packageFound)
            return string.Empty;

        return _version >= new Version(3, 0, 0)
            ? "UnityEditor.DeviceSimulation.SimulatorWindow"
            : "Unity.DeviceSimulator.SimulatorWindow";
    }
    
    private static bool TryGetPackageVersion(out Version version)
    {
        version = new Version();
        var packagesPath = $"{Application.dataPath}/../Packages/manifest.json";
        var versionGroup = "";

        if (!File.Exists(packagesPath))
            return false;
        
        try
        {
            var packageField = File.ReadLines(packagesPath)
                .FirstOrDefault(x => x.Contains("com.unity.device-simulator"));

            if (string.IsNullOrEmpty(packageField))
                return false;
            
            var matches = Regex.Matches(packageField, "\".*?\"");
            if (matches.Count == 0)
                return false;

            versionGroup = matches[matches.Count - 1].Value.Replace("\"", "");
            var previewIndex = versionGroup.IndexOf("-preview", StringComparison.Ordinal);
            if (previewIndex > -1)
                versionGroup = versionGroup.Substring(0, previewIndex);

            version = Version.Parse(versionGroup);
        }
        catch (Exception ex)
        {
            var message = string.IsNullOrEmpty(versionGroup)
                ? $"Can't get Device Simulator version (version group is {versionGroup}): {ex.Message}"
                : $"Can't get Device Simulator version: {ex.Message}";
            Debug.LogError(message);
            
            return false;
        }

        return true;
    }
}
#endif

Updated to use with Device Simulator 3.0.0 and newer.