diff --git a/testapps/TelephonyRegistryTestApp/Android.mk b/testapps/TelephonyRegistryTestApp/Android.mk
new file mode 100644
index 0000000..ed1f2a3
--- /dev/null
+++ b/testapps/TelephonyRegistryTestApp/Android.mk
@@ -0,0 +1,17 @@
+LOCAL_PATH:= $(call my-dir)
+
+include $(CLEAR_VARS)
+
+src_dirs := src
+res_dirs := res
+
+LOCAL_SRC_FILES := $(call all-java-files-under, $(src_dirs))
+LOCAL_RESOURCE_DIR := $(addprefix $(LOCAL_PATH)/, $(res_dirs))
+
+LOCAL_PACKAGE_NAME := TelephonyRegistryTestApp
+
+LOCAL_CERTIFICATE := platform
+LOCAL_MODULE_TAGS := tests
+#LOCAL_MODULE_TAGS := debug
+
+include $(BUILD_PACKAGE)
diff --git a/testapps/TelephonyRegistryTestApp/AndroidManifest.xml b/testapps/TelephonyRegistryTestApp/AndroidManifest.xml
new file mode 100644
index 0000000..5f19509
--- /dev/null
+++ b/testapps/TelephonyRegistryTestApp/AndroidManifest.xml
@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2017 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+          package="com.android.phone.testapps.telephonyregistry">
+    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
+    <uses-permission android:name="android.permission.READ_PHONE_STATE"/>
+    <application android:label="TelephonyRegistryTestApp">
+        <activity
+            android:name=".TelephonyRegistryTestApp"
+            android:label="TelephonyRegistryTestApp">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+</manifest>
+
diff --git a/testapps/TelephonyRegistryTestApp/res/layout/activity_main.xml b/testapps/TelephonyRegistryTestApp/res/layout/activity_main.xml
new file mode 100644
index 0000000..405efe2
--- /dev/null
+++ b/testapps/TelephonyRegistryTestApp/res/layout/activity_main.xml
@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2017 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License
+  -->
+
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical" >
+    <ScrollView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="vertical"
+            android:id="@+id/events">
+        </LinearLayout>
+    </ScrollView>
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal">
+        <Button
+            android:id="@+id/queryCellLocationButton"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_row="0"
+            android:layout_column="0"
+            android:text="@string/query_cell_location_button" />
+        <Button
+            android:id="@+id/registerButton"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_row="0"
+            android:layout_column="0"
+            android:text="@string/register_button" />
+    </LinearLayout>
+</LinearLayout>
diff --git a/testapps/TelephonyRegistryTestApp/res/values/donottranslate_strings.xml b/testapps/TelephonyRegistryTestApp/res/values/donottranslate_strings.xml
new file mode 100644
index 0000000..897b83e
--- /dev/null
+++ b/testapps/TelephonyRegistryTestApp/res/values/donottranslate_strings.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2017 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License
+  -->
+
+<resources>
+    <string name="register_button">Register</string>
+    <string name="query_cell_location_button">Query</string>
+</resources>
\ No newline at end of file
diff --git a/testapps/TelephonyRegistryTestApp/src/com/android/phone/testapps/telephonyregistry/TelephonyRegistryTestApp.java b/testapps/TelephonyRegistryTestApp/src/com/android/phone/testapps/telephonyregistry/TelephonyRegistryTestApp.java
new file mode 100644
index 0000000..e423619
--- /dev/null
+++ b/testapps/TelephonyRegistryTestApp/src/com/android/phone/testapps/telephonyregistry/TelephonyRegistryTestApp.java
@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.phone.testapps.telephonyregistry;
+
+import android.app.Activity;
+import android.app.Notification;
+import android.app.NotificationChannel;
+import android.app.NotificationManager;
+import android.os.Bundle;
+import android.provider.Telephony;
+import android.telephony.CellInfo;
+import android.telephony.CellLocation;
+import android.telephony.PhoneStateListener;
+import android.telephony.TelephonyManager;
+import android.util.SparseArray;
+import android.widget.Button;
+import android.widget.CheckBox;
+import android.widget.LinearLayout;
+import android.widget.Toast;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class TelephonyRegistryTestApp extends Activity {
+    private TelephonyManager telephonyManager;
+    private NotificationManager notificationManager;
+    private int mSelectedEvents = 0;
+    private static final String NOTIFICATION_CHANNEL = "registryUpdate";
+
+    private static final SparseArray<String> EVENTS = new SparseArray<String>() {{
+        put(PhoneStateListener.LISTEN_SERVICE_STATE, "SERVICE_STATE");
+        put(PhoneStateListener.LISTEN_MESSAGE_WAITING_INDICATOR, "MESSAGE_WAITING_INDICATOR");
+        put(PhoneStateListener.LISTEN_CALL_FORWARDING_INDICATOR, "CALL_FORWARDING_INDICATOR");
+        put(PhoneStateListener.LISTEN_CELL_LOCATION, "CELL_LOCATION");
+        put(PhoneStateListener.LISTEN_CALL_STATE, "CALL_STATE");
+        put(PhoneStateListener.LISTEN_DATA_CONNECTION_STATE, "DATA_CONNECTION_STATE");
+        put(PhoneStateListener.LISTEN_DATA_ACTIVITY, "DATA_ACTIVITY");
+        put(PhoneStateListener.LISTEN_SIGNAL_STRENGTHS, "SIGNAL_STRENGTHS");
+        put(PhoneStateListener.LISTEN_OTASP_CHANGED, "OTASP_CHANGED");
+        put(PhoneStateListener.LISTEN_CELL_INFO, "CELL_INFO");
+        put(PhoneStateListener.LISTEN_PRECISE_CALL_STATE, "PRECISE_CALL_STATE");
+        put(PhoneStateListener.LISTEN_PRECISE_DATA_CONNECTION_STATE,
+                "PRECISE_DATA_CONNECTION_STATE");
+        put(PhoneStateListener.LISTEN_VOLTE_STATE, "VOLTE_STATE");
+        put(PhoneStateListener.LISTEN_CARRIER_NETWORK_CHANGE, "CARRIER_NETWORK_CHANGE");
+        put(PhoneStateListener.LISTEN_VOICE_ACTIVATION_STATE, "VOICE_ACTIVATION_STATE");
+        put(PhoneStateListener.LISTEN_DATA_ACTIVATION_STATE, "DATA_ACTIVATION_STATE");
+    }};
+
+    private final PhoneStateListener phoneStateListener = new PhoneStateListener() {
+        @Override
+        public void onCellLocationChanged(CellLocation location) {
+            notify("onCellLocationChanged", location);
+        }
+
+        @Override
+        public void onCellInfoChanged(List<CellInfo> cellInfo) {
+            notify("onCellInfoChanged", cellInfo);
+        }
+
+        private void notify(String method, Object data) {
+            Notification.Builder builder = new Notification.Builder(TelephonyRegistryTestApp.this,
+                    NOTIFICATION_CHANNEL);
+            Notification notification = builder.setSmallIcon(android.R.drawable.sym_def_app_icon)
+                    .setContentTitle("Registry update: " + method)
+                    .setContentText(data == null ? "null" : data.toString())
+                    .build();
+            notificationManager.notify(0, notification);
+        }
+    };
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_main);
+
+        telephonyManager = getSystemService(TelephonyManager.class);
+
+        LinearLayout eventContainer = (LinearLayout) findViewById(R.id.events);
+        for (int i = 0; i < EVENTS.size(); i++) {
+            CheckBox box = new CheckBox(this);
+            box.setText(EVENTS.valueAt(i));
+            final int eventCode = EVENTS.keyAt(i);
+            box.setOnCheckedChangeListener((buttonView, isChecked) -> {
+                if (buttonView.isChecked()) {
+                    mSelectedEvents |= eventCode;
+                } else {
+                    mSelectedEvents &= ~eventCode;
+                }
+            });
+            eventContainer.addView(box);
+        }
+
+        Button registerButton = (Button) findViewById(R.id.registerButton);
+        registerButton.setOnClickListener(v ->
+                telephonyManager.listen(phoneStateListener, mSelectedEvents));
+
+        Button queryCellLocationButton = findViewById(R.id.queryCellLocationButton);
+        queryCellLocationButton.setOnClickListener(v -> {
+            List<CellInfo> cellInfos = telephonyManager.getAllCellInfo();
+            String cellInfoText;
+            if (cellInfos == null || cellInfos.size() == 0) {
+                cellInfoText = "null";
+            } else {
+                cellInfoText = cellInfos.stream().map(CellInfo::toString)
+                        .collect(Collectors.joining(","));
+            }
+            Toast.makeText(TelephonyRegistryTestApp.this, "queryCellInfo: " + cellInfoText,
+                    Toast.LENGTH_SHORT).show();
+        });
+
+        notificationManager = getSystemService(NotificationManager.class);
+        NotificationChannel channel = new NotificationChannel(NOTIFICATION_CHANNEL,
+                "Telephony Registry updates", NotificationManager.IMPORTANCE_HIGH);
+        notificationManager.createNotificationChannel(channel);
+    }
+}