diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/UIDebuggerFlipperPlugin.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/UIDebuggerFlipperPlugin.kt
new file mode 100644
index 000000000..0d71e148c
--- /dev/null
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/UIDebuggerFlipperPlugin.kt
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.flipper.plugins.uidebugger
+
+import com.facebook.flipper.core.FlipperConnection
+import com.facebook.flipper.core.FlipperPlugin
+import com.facebook.flipper.plugins.uidebugger.commands.CommandRegister
+import com.facebook.flipper.plugins.uidebugger.commands.Context
+import com.facebook.flipper.plugins.uidebugger.commands.GetRoot
+
+class UIDebuggerFlipperPlugin : FlipperPlugin {
+  private var context: Context = Context()
+  private var connection: FlipperConnection? = null
+
+  override fun getId(): String {
+    return "UIDebugger"
+  }
+
+  @Throws(Exception::class)
+  override fun onConnect(connection: FlipperConnection) {
+    this.connection = connection
+    registerCommands(connection)
+  }
+
+  @Throws(Exception::class)
+  override fun onDisconnect() {
+    this.connection = null
+  }
+
+  override fun runInBackground(): Boolean {
+    return true
+  }
+
+  fun registerCommands(connection: FlipperConnection) {
+    CommandRegister.register(connection, GetRoot(context))
+  }
+}
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/Command.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/Command.kt
new file mode 100644
index 000000000..9e7d7c27b
--- /dev/null
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/Command.kt
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.flipper.plugins.uidebugger.commands
+
+import com.facebook.flipper.core.FlipperObject
+import com.facebook.flipper.core.FlipperReceiver
+import com.facebook.flipper.core.FlipperResponder
+import com.facebook.flipper.plugins.common.MainThreadFlipperReceiver
+
+/** An interface for extensions to the UIDebugger plugin */
+abstract class Command(val context: Context) {
+  /** The command identifier to respond to */
+  abstract fun identifier(): String
+  /** Execute the command */
+  abstract fun execute(params: FlipperObject, response: FlipperResponder)
+  /** Receiver which is the low-level handler for the incoming request */
+  open fun receiver(): FlipperReceiver {
+    return object : MainThreadFlipperReceiver() {
+      @kotlin.Throws(java.lang.Exception::class)
+      override fun onReceiveOnMainThread(params: FlipperObject, responder: FlipperResponder) {
+        execute(params, responder)
+      }
+    }
+  }
+}
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/CommandRegister.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/CommandRegister.kt
new file mode 100644
index 000000000..054977382
--- /dev/null
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/CommandRegister.kt
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.flipper.plugins.uidebugger.commands
+
+import com.facebook.flipper.core.FlipperConnection
+
+sealed class CommandRegister {
+  companion object {
+    fun <T> register(connection: FlipperConnection, cmd: T) where T : Command {
+      connection.receive(cmd.identifier(), cmd.receiver())
+    }
+  }
+}
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/Context.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/Context.kt
new file mode 100644
index 000000000..dfef7b373
--- /dev/null
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/Context.kt
@@ -0,0 +1,10 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.flipper.plugins.uidebugger.commands
+
+class Context() {}
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/GetRoot.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/GetRoot.kt
new file mode 100644
index 000000000..d3e17206d
--- /dev/null
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/commands/GetRoot.kt
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.flipper.plugins.uidebugger.commands
+
+import com.facebook.flipper.core.FlipperObject
+import com.facebook.flipper.core.FlipperResponder
+
+class GetRoot(context: Context) : Command(context) {
+  override fun identifier(): String {
+    return "getRoot"
+  }
+
+  override fun execute(params: FlipperObject, response: FlipperResponder) {}
+}
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/ApplicationObserver.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/ApplicationObserver.kt
new file mode 100644
index 000000000..650e0459d
--- /dev/null
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/ApplicationObserver.kt
@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.flipper.plugins.uidebugger.core
+
+import android.app.Activity
+import android.app.Application
+import android.os.Bundle
+import android.view.View
+import java.lang.ref.WeakReference
+
+class ApplicationObserver(val application: Application) : Application.ActivityLifecycleCallbacks {
+  interface ActivityStackChangedListener {
+    fun onActivityStackChanged(stack: List<Activity>)
+  }
+
+  interface ActivityDestroyedListener {
+    fun onActivityDestroyed(activity: Activity)
+  }
+
+  private val rootsResolver: RootViewResolver
+  private val activities: MutableList<WeakReference<Activity>>
+  private var activityStackChangedlistener: ActivityStackChangedListener? = null
+  private var activityDestroyedListener: ActivityDestroyedListener? = null
+
+  override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) {
+    activities.add(WeakReference<Activity>(activity))
+    activityStackChangedlistener?.let { listener ->
+      listener.onActivityStackChanged(this.activitiesStack)
+    }
+  }
+  override fun onActivityStarted(activity: Activity) {}
+  override fun onActivityResumed(activity: Activity) {}
+  override fun onActivityPaused(activity: Activity) {}
+  override fun onActivityStopped(activity: Activity) {}
+  override fun onActivitySaveInstanceState(activity: Activity, outState: Bundle) {}
+  override fun onActivityDestroyed(activity: Activity) {
+    val activityIterator: MutableIterator<WeakReference<Activity>> = activities.iterator()
+
+    while (activityIterator.hasNext()) {
+      if (activityIterator.next().get() === activity) {
+        activityIterator.remove()
+      }
+    }
+
+    activityDestroyedListener?.let { listener -> listener.onActivityDestroyed(activity) }
+
+    activityStackChangedlistener?.let { listener ->
+      listener.onActivityStackChanged(this.activitiesStack)
+    }
+  }
+
+  fun setActivityStackChangedListener(listener: ActivityStackChangedListener?) {
+    activityStackChangedlistener = listener
+  }
+
+  fun setActivityDestroyedListener(listener: ActivityDestroyedListener?) {
+    activityDestroyedListener = listener
+  }
+
+  val activitiesStack: List<Activity>
+    get() {
+      val stack: MutableList<Activity> = ArrayList<Activity>(activities.size)
+      val activityIterator: MutableIterator<WeakReference<Activity>> = activities.iterator()
+      while (activityIterator.hasNext()) {
+        val activity: Activity? = activityIterator.next().get()
+        if (activity == null) {
+          activityIterator.remove()
+        } else {
+          stack.add(activity)
+        }
+      }
+      return stack
+    }
+
+  val rootViews: List<View>
+    get() {
+      val roots = rootsResolver.listActiveRootViews()
+      roots?.let { roots ->
+        val viewRoots: MutableList<View> = ArrayList<View>(roots.size)
+        for (root in roots) {
+          viewRoots.add(root.view)
+        }
+        return viewRoots
+      }
+
+      return emptyList()
+    }
+
+  init {
+    rootsResolver = RootViewResolver()
+    application.registerActivityLifecycleCallbacks(this)
+    activities = ArrayList<WeakReference<Activity>>()
+  }
+}
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/LayoutVisitor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/LayoutVisitor.kt
new file mode 100644
index 000000000..6e58fbadc
--- /dev/null
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/LayoutVisitor.kt
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.flipper.plugins.uidebugger.core
+
+import android.view.View
+import android.view.ViewGroup
+
+/** Layout Visitor traverses the entire view hierarchy from a given root. */
+class LayoutVisitor(val visitor: Visitor) {
+  interface Visitor {
+    fun visit(view: View)
+  }
+
+  fun traverse(view: View) {
+    visitor.visit(view)
+
+    if (view is ViewGroup) {
+      val viewGroup = view as ViewGroup
+      val childCount = viewGroup.childCount - 1
+      for (i in 0 until childCount) {
+        val child = viewGroup.getChildAt(i)
+        traverse(child)
+      }
+    }
+  }
+
+  companion object {
+    fun create(visitor: Visitor): LayoutVisitor {
+      return LayoutVisitor(visitor)
+    }
+  }
+}
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/RootViewResolver.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/RootViewResolver.kt
new file mode 100644
index 000000000..7929033b1
--- /dev/null
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/RootViewResolver.kt
@@ -0,0 +1,190 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.flipper.plugins.uidebugger.core
+
+import android.os.Build
+import android.view.View
+import android.view.WindowManager
+import java.lang.reflect.Field
+import java.lang.reflect.InvocationTargetException
+import java.lang.reflect.Modifier
+import java.util.ArrayList
+import java.util.List
+
+/**
+ * Provides access to all root views in an application.
+ *
+ * 95% of the time this is unnecessary and we can operate solely on current Activity's root view as
+ * indicated by getWindow().getDecorView(). However in the case of popup windows, menus, and dialogs
+ * the actual view hierarchy we should be operating on is not accessible thru public apis.
+ *
+ * In the spirit of degrading gracefully when new api levels break compatibility, callers should
+ * handle a list of size 0 by assuming getWindow().getDecorView() on the currently resumed activity
+ * is the sole root - this assumption will be correct often enough.
+ *
+ * Obviously, you need to be on the main thread to use this.
+ */
+class RootViewResolver {
+  private var initialized = false
+  private var windowManagerObj: Any? = null
+  private var viewsField: Field? = null
+  private var paramsField: Field? = null
+
+  class RootView(val view: View, val param: WindowManager.LayoutParams)
+  interface Listener {
+    fun onRootViewAdded(rootView: View)
+    fun onRootViewRemoved(rootView: View)
+    fun onRootViewsChanged(rootView: List<View>)
+  }
+
+  class ObservableArrayList() : ArrayList<View>() {
+    private var listener: Listener? = null
+    fun setListener(listener: Listener?) {
+      this.listener = listener
+    }
+
+    override fun add(value: View): Boolean {
+      val ret = super.add(value)
+      listener?.let { l ->
+        l.onRootViewAdded(value)
+        l.onRootViewsChanged(this as List<View>)
+      }
+      return ret
+    }
+
+    override fun remove(value: View): Boolean {
+      val ret = super.remove(value)
+      listener?.let { l ->
+        l.onRootViewRemoved(value)
+        l.onRootViewsChanged(this as List<View>)
+      }
+
+      return ret
+    }
+
+    override fun removeAt(index: Int): View {
+      val view = super.removeAt(index)
+      listener?.let { l ->
+        l.onRootViewRemoved(view)
+        l.onRootViewsChanged(this as List<View>)
+      }
+      return view
+    }
+  }
+
+  fun attachListener(listener: Listener?) {
+    if (Build.VERSION.SDK_INT < 19 || listener == null) {
+      // We don't have a use for this on older APIs. If you do then modify accordingly :)
+      return
+    }
+    if (!initialized) {
+      initialize()
+    }
+    try {
+      viewsField?.let { vf ->
+        // Forgive me father for I have sinned...
+        val modifiers = Field::class.java.getDeclaredField("accessFlags")
+        modifiers.isAccessible = true
+        modifiers.setInt(vf, vf.modifiers and Modifier.FINAL.inv())
+
+        val views = vf[windowManagerObj] as List<View>
+
+        val observableViews = ObservableArrayList()
+        observableViews.setListener(listener)
+        observableViews.addAll(views)
+
+        vf[windowManagerObj] = observableViews
+      }
+    } catch (e: Throwable) {}
+  }
+
+  /**
+   * Lists the active root views in an application at this moment.
+   *
+   * @return a list of all the active root views in the application.
+   * @throws IllegalStateException if invoked from a thread besides the main thread.
+   */
+  fun listActiveRootViews(): List<RootView>? {
+    if (!initialized) {
+      initialize()
+    }
+    if (null == windowManagerObj) {
+      return null
+    }
+    if (null == viewsField) {
+      return null
+    }
+    if (null == paramsField) {
+      return null
+    }
+    var views: List<View>? = null
+    var params: List<WindowManager.LayoutParams>? = null
+    try {
+      viewsField?.let { field ->
+        if (Build.VERSION.SDK_INT < 19) {
+          val arr = field[windowManagerObj] as Array<View>
+          views = arr.toList() as List<View>
+        } else {
+          views = field[windowManagerObj] as List<View>
+        }
+      }
+
+      paramsField?.let { field ->
+        if (Build.VERSION.SDK_INT < 19) {
+          val arr = field[windowManagerObj] as Array<WindowManager.LayoutParams>
+          params = arr.toList() as List<WindowManager.LayoutParams>
+        } else {
+          params = field[windowManagerObj] as List<WindowManager.LayoutParams>
+        }
+      }
+    } catch (re: RuntimeException) {
+      return null
+    } catch (iae: IllegalAccessException) {
+      return null
+    }
+
+    val roots: ArrayList<RootView> = ArrayList()
+    views?.let { views ->
+      params?.let { params ->
+        for (i in views.indices) {
+          roots.add(RootView(views[i], params[i]))
+        }
+      }
+    }
+
+    return roots as List<RootView>
+  }
+
+  private fun initialize() {
+    initialized = true
+    val accessClass =
+        if (Build.VERSION.SDK_INT > 16) WINDOW_MANAGER_GLOBAL_CLAZZ else WINDOW_MANAGER_IMPL_CLAZZ
+    val instanceMethod = if (Build.VERSION.SDK_INT > 16) GET_GLOBAL_INSTANCE else GET_DEFAULT_IMPL
+    try {
+      val clazz = Class.forName(accessClass)
+      val getMethod = clazz.getMethod(instanceMethod)
+      windowManagerObj = getMethod.invoke(null)
+      viewsField = clazz.getDeclaredField(VIEWS_FIELD)
+      viewsField?.let { vf -> vf.setAccessible(true) }
+      paramsField = clazz.getDeclaredField(WINDOW_PARAMS_FIELD)
+      paramsField?.let { pf -> pf.setAccessible(true) }
+    } catch (ite: InvocationTargetException) {} catch (cnfe: ClassNotFoundException) {} catch (
+        nsfe: NoSuchFieldException) {} catch (nsme: NoSuchMethodException) {} catch (
+        re: RuntimeException) {} catch (iae: IllegalAccessException) {}
+  }
+
+  companion object {
+    private val TAG = RootViewResolver::class.java.simpleName
+    private const val WINDOW_MANAGER_IMPL_CLAZZ = "android.view.WindowManagerImpl"
+    private const val WINDOW_MANAGER_GLOBAL_CLAZZ = "android.view.WindowManagerGlobal"
+    private const val VIEWS_FIELD = "mViews"
+    private const val WINDOW_PARAMS_FIELD = "mParams"
+    private const val GET_DEFAULT_IMPL = "getDefault"
+    private const val GET_GLOBAL_INSTANCE = "getInstance"
+  }
+}
diff --git a/android/src/test/java/com/facebook/flipper/plugins/uidebugger/UIDebuggerFlipperPluginTest.kt b/android/src/test/java/com/facebook/flipper/plugins/uidebugger/UIDebuggerFlipperPluginTest.kt
new file mode 100644
index 000000000..575dc6772
--- /dev/null
+++ b/android/src/test/java/com/facebook/flipper/plugins/uidebugger/UIDebuggerFlipperPluginTest.kt
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.flipper.plugins.uidebugger
+
+import org.junit.Assert
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+class UIDebuggerFlipperPluginTest {
+  @Throws(Exception::class)
+  @Test
+  fun emptyTest() {
+    var plugin = UIDebuggerFlipperPlugin()
+    Assert.assertNotNull(plugin)
+  }
+}