diff --git a/src/com/android/settings/DevelopmentSettings.java b/src/com/android/settings/DevelopmentSettings.java
index 6468f94..6a8caec 100644
--- a/src/com/android/settings/DevelopmentSettings.java
+++ b/src/com/android/settings/DevelopmentSettings.java
@@ -74,6 +74,16 @@
         implements DialogInterface.OnClickListener, DialogInterface.OnDismissListener,
                 OnPreferenceChangeListener, CompoundButton.OnCheckedChangeListener {
 
+    /**
+     * Preference file were development settings prefs are stored.
+     */
+    public static final String PREF_FILE = "development";
+
+    /**
+     * Whether to show the development settings to the user.  Default is false.
+     */
+    public static final String PREF_SHOW = "show";
+
     private static final String ENABLE_ADB = "enable_adb";
     private static final String KEEP_SCREEN_ON = "keep_screen_on";
     private static final String ALLOW_MOCK_LOCATION = "allow_mock_location";
@@ -350,6 +360,7 @@
             Settings.Global.putInt(getActivity().getContentResolver(),
                     Settings.Global.DEVELOPMENT_SETTINGS_ENABLED, 1);
             mLastEnabledState = true;
+            mEnabledSwitch.setChecked(mLastEnabledState);
             setPrefsEnabledState(mLastEnabledState);
         }
     }
diff --git a/src/com/android/settings/DeviceInfoSettings.java b/src/com/android/settings/DeviceInfoSettings.java
index 5f35871..f113da1 100644
--- a/src/com/android/settings/DeviceInfoSettings.java
+++ b/src/com/android/settings/DeviceInfoSettings.java
@@ -17,10 +17,8 @@
 package com.android.settings;
 
 import android.app.Activity;
-import android.content.ComponentName;
+import android.content.Context;
 import android.content.Intent;
-import android.content.pm.PackageManager;
-import android.content.pm.ResolveInfo;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.SELinux;
@@ -30,13 +28,12 @@
 import android.preference.Preference;
 import android.preference.PreferenceGroup;
 import android.preference.PreferenceScreen;
-import android.provider.Settings;
 import android.util.Log;
+import android.widget.Toast;
 
 import java.io.BufferedReader;
 import java.io.FileReader;
 import java.io.IOException;
-import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -68,6 +65,8 @@
     private static final String PROPERTY_EQUIPMENT_ID = "ro.ril.fccid";
 
     long[] mHits = new long[3];
+    int mDevHitCountdown;
+    Toast mDevHitToast;
 
     @Override
     public void onCreate(Bundle icicle) {
@@ -82,6 +81,7 @@
         setValueSummary(KEY_EQUIPMENT_ID, PROPERTY_EQUIPMENT_ID);
         setStringSummary(KEY_DEVICE_MODEL, Build.MODEL);
         setStringSummary(KEY_BUILD_NUMBER, Build.DISPLAY);
+        findPreference(KEY_BUILD_NUMBER).setEnabled(true);
         findPreference(KEY_KERNEL_VERSION).setSummary(getFormattedKernelVersion());
 
         if (!SELinux.isSELinuxEnabled()) {
@@ -148,6 +148,15 @@
     }
 
     @Override
+    public void onResume() {
+        super.onResume();
+        mDevHitCountdown = getActivity().getSharedPreferences(DevelopmentSettings.PREF_FILE,
+                Context.MODE_PRIVATE).getBoolean(DevelopmentSettings.PREF_SHOW,
+                        android.os.Build.TYPE.equals("eng")) ? -1 : 7;
+        mDevHitToast = null;
+    }
+
+    @Override
     public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
         if (preference.getKey().equals(KEY_FIRMWARE_VERSION)) {
             System.arraycopy(mHits, 1, mHits, 0, mHits.length-1);
@@ -162,6 +171,36 @@
                     Log.e(LOG_TAG, "Unable to start activity " + intent.toString());
                 }
             }
+        } else if (preference.getKey().equals(KEY_BUILD_NUMBER)) {
+            if (mDevHitCountdown > 0) {
+                mDevHitCountdown--;
+                if (mDevHitCountdown == 0) {
+                    getActivity().getSharedPreferences(DevelopmentSettings.PREF_FILE,
+                            Context.MODE_PRIVATE).edit().putBoolean(
+                                    DevelopmentSettings.PREF_SHOW, true).apply();
+                    if (mDevHitToast != null) {
+                        mDevHitToast.cancel();
+                    }
+                    mDevHitToast = Toast.makeText(getActivity(), R.string.show_dev_on,
+                            Toast.LENGTH_LONG);
+                    mDevHitToast.show();
+                } else if (mDevHitCountdown > 0) {
+                    if (mDevHitToast != null) {
+                        mDevHitToast.cancel();
+                    }
+                    mDevHitToast = Toast.makeText(getActivity(), getResources().getString(
+                            R.string.show_dev_countdown, mDevHitCountdown),
+                            Toast.LENGTH_SHORT);
+                    mDevHitToast.show();
+                }
+            } else if (mDevHitCountdown < 0) {
+                if (mDevHitToast != null) {
+                    mDevHitToast.cancel();
+                }
+                mDevHitToast = Toast.makeText(getActivity(), R.string.show_dev_already,
+                        Toast.LENGTH_LONG);
+                mDevHitToast.show();
+            }
         }
         return super.onPreferenceTreeClick(preferenceScreen, preference);
     }
diff --git a/src/com/android/settings/Settings.java b/src/com/android/settings/Settings.java
index b52c2e2..4314f2d 100644
--- a/src/com/android/settings/Settings.java
+++ b/src/com/android/settings/Settings.java
@@ -34,6 +34,7 @@
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
+import android.content.SharedPreferences;
 import android.content.pm.ActivityInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
@@ -121,6 +122,9 @@
             R.id.accessibility_settings
     };
 
+    private SharedPreferences mDevelopmentPreferences;
+    private SharedPreferences.OnSharedPreferenceChangeListener mDevelopmentPreferencesListener;
+
     // TODO: Update Call Settings based on airplane mode state.
 
     protected HashMap<Integer, Integer> mHeaderIndexMap = new HashMap<Integer, Integer>();
@@ -139,6 +143,9 @@
         mAuthenticatorHelper.updateAuthDescriptions(this);
         mAuthenticatorHelper.onAccountsUpdated(this, null);
 
+        mDevelopmentPreferences = getSharedPreferences(DevelopmentSettings.PREF_FILE,
+                Context.MODE_PRIVATE);
+
         getMetaData();
         mInLocalHeaderSwitch = true;
         super.onCreate(savedInstanceState);
@@ -195,6 +202,15 @@
     public void onResume() {
         super.onResume();
 
+        mDevelopmentPreferencesListener = new SharedPreferences.OnSharedPreferenceChangeListener() {
+            @Override
+            public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
+                invalidateHeaders();
+            }
+        };
+        mDevelopmentPreferences.registerOnSharedPreferenceChangeListener(
+                mDevelopmentPreferencesListener);
+
         ListAdapter listAdapter = getListAdapter();
         if (listAdapter instanceof HeaderAdapter) {
             ((HeaderAdapter) listAdapter).resume();
@@ -210,6 +226,10 @@
         if (listAdapter instanceof HeaderAdapter) {
             ((HeaderAdapter) listAdapter).pause();
         }
+
+        mDevelopmentPreferences.unregisterOnSharedPreferenceChangeListener(
+                mDevelopmentPreferencesListener);
+        mDevelopmentPreferencesListener = null;
     }
 
     @Override
@@ -390,7 +410,12 @@
     }
 
     private void updateHeaderList(List<Header> target) {
+        final boolean showDev = mDevelopmentPreferences.getBoolean(
+                DevelopmentSettings.PREF_SHOW,
+                android.os.Build.TYPE.equals("eng"));
         int i = 0;
+
+        mHeaderIndexMap.clear();
         while (i < target.size()) {
             Header header = target.get(i);
             // Ids are integers, so downcasting
@@ -400,12 +425,12 @@
             } else if (id == R.id.wifi_settings) {
                 // Remove WiFi Settings if WiFi service is not available.
                 if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_WIFI)) {
-                    target.remove(header);
+                    target.remove(i);
                 }
             } else if (id == R.id.bluetooth_settings) {
                 // Remove Bluetooth Settings if Bluetooth service is not available.
                 if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)) {
-                    target.remove(header);
+                    target.remove(i);
                 }
             } else if (id == R.id.data_usage_settings) {
                 // Remove data usage when kernel module not enabled
@@ -413,7 +438,7 @@
                         .asInterface(ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE));
                 try {
                     if (!netManager.isBandwidthControlEnabled()) {
-                        target.remove(header);
+                        target.remove(i);
                     }
                 } catch (RemoteException e) {
                     // ignored
@@ -425,12 +450,17 @@
                 if (!UserHandle.MU_ENABLED
                         || !UserManager.supportsMultipleUsers()
                         || Utils.isMonkeyRunning()) {
-                    target.remove(header);
+                    target.remove(i);
+                }
+            } else if (id == R.id.development_settings) {
+                if (!showDev) {
+                    target.remove(i);
                 }
             }
+
             if (UserHandle.MU_ENABLED && UserHandle.myUserId() != 0
                     && !ArrayUtils.contains(SETTINGS_FOR_RESTRICTED, id)) {
-                target.remove(header);
+                target.remove(i);
             }
 
             // Increment if the current one wasn't removed by the Utils code.