diff --git a/xwords4/android/app/build.gradle b/xwords4/android/app/build.gradle
index 0fd4aee24..29985fdfa 100644
--- a/xwords4/android/app/build.gradle
+++ b/xwords4/android/app/build.gradle
@@ -313,11 +313,11 @@ ext {
 }
 
 dependencies {
-    implementation "com.android.support:support-v4:$SUPPORT_LIB_VERSION"
-    implementation "com.android.support:support-compat:$SUPPORT_LIB_VERSION"
+    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
+    implementation 'androidx.core:core:1.0.0'
 
-    implementation "android.arch.lifecycle:extensions:1.1.1"
-    annotationProcessor "android.arch.lifecycle:compiler:1.1.1"
+    implementation 'androidx.lifecycle:lifecycle-extensions:2.0.0'
+    annotationProcessor 'androidx.lifecycle:lifecycle-compiler:2.0.0'
 
     // 2.6.8 is probably as far forward as I can go without upping my
     // min-supported SDK version
diff --git a/xwords4/android/app/src/main/AndroidManifest.xml b/xwords4/android/app/src/main/AndroidManifest.xml
index 8d1e0d07b..b53bde654 100644
--- a/xwords4/android/app/src/main/AndroidManifest.xml
+++ b/xwords4/android/app/src/main/AndroidManifest.xml
@@ -43,7 +43,7 @@
                android:theme="@style/AppTheme"
                >
 
-    <provider android:name="android.support.v4.content.FileProvider"
+    <provider android:name="androidx.core.content.FileProvider"
               android:authorities="${applicationId}.provider"
               android:exported="false"
               android:grantUriPermissions="true"
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/AboutAlert.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/AboutAlert.java
index 7247ea6fa..4257232c0 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/AboutAlert.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/AboutAlert.java
@@ -25,8 +25,6 @@ import android.content.Context;
 import android.content.DialogInterface.OnClickListener;
 import android.content.DialogInterface;
 import android.os.Bundle;
-import android.support.v4.app.DialogFragment;
-import android.view.View;
 import android.view.View;
 import android.widget.TextView;
 
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DBAlert.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DBAlert.java
index 9a873d319..989cb1d26 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DBAlert.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DBAlert.java
@@ -20,15 +20,8 @@
 package org.eehouse.android.xw4;
 
 import android.app.Dialog;
-import android.content.DialogInterface.OnClickListener;
-import android.content.DialogInterface;
-import android.os.Bundle;
 import android.os.Bundle;
 import android.os.Handler;
-import android.support.v4.app.DialogFragment;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
 
 import org.eehouse.android.xw4.loc.LocUtils;
 
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DelegateBase.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DelegateBase.java
index cc7f6106c..76dbbe2ff 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DelegateBase.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DelegateBase.java
@@ -27,10 +27,7 @@ import android.content.DialogInterface.OnCancelListener;
 import android.content.DialogInterface.OnClickListener;
 import android.content.DialogInterface;
 import android.content.Intent;
-import android.graphics.Point;
-import android.graphics.Rect;
 import android.os.Bundle;
-import android.support.v4.app.DialogFragment;
 import android.view.ContextMenu.ContextMenuInfo;
 import android.view.ContextMenu;
 import android.view.LayoutInflater;
@@ -44,7 +41,6 @@ import android.widget.EditText;
 import android.widget.TextView;
 
 import org.eehouse.android.xw4.DlgDelegate.Action;
-import org.eehouse.android.xw4.DlgDelegate.ActionPair;
 import org.eehouse.android.xw4.DlgDelegate.ConfirmThenBuilder;
 import org.eehouse.android.xw4.DlgDelegate.DlgClickNotify;
 import org.eehouse.android.xw4.DlgDelegate.NotAgainBuilder;
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DlgDelegate.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DlgDelegate.java
index 80014cf7f..fbed46ef4 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DlgDelegate.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DlgDelegate.java
@@ -22,15 +22,9 @@ package org.eehouse.android.xw4;
 
 import android.app.Activity;
 import android.app.AlertDialog;
-import android.app.Dialog;
-import android.support.v4.app.DialogFragment;
 import android.app.ProgressDialog;
-import android.content.Context;
 import android.content.DialogInterface.OnCancelListener;
-import android.content.DialogInterface.OnClickListener;
-import android.os.Bundle;
 import android.os.Handler;
-import android.view.View;
 
 import java.io.Serializable;
 
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DlgDelegateAlert.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DlgDelegateAlert.java
index 5a2ee9534..03d0980b0 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DlgDelegateAlert.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/DlgDelegateAlert.java
@@ -26,7 +26,7 @@ import android.content.Context;
 import android.content.DialogInterface.OnClickListener;
 import android.content.DialogInterface;
 import android.os.Bundle;
-import android.support.v4.app.DialogFragment;
+
 import org.eehouse.android.xw4.DlgDelegate.Action;
 import org.eehouse.android.xw4.DlgDelegate.ActionPair;
 import org.eehouse.android.xw4.DlgDelegate.DlgClickNotify;
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/GameLock.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/GameLock.java
index 9f355bd9b..188f7e1c4 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/GameLock.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/GameLock.java
@@ -29,7 +29,7 @@ import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 // Implements read-locks and write-locks per game.  A read lock is
 // obtainable when other read locks are granted but not when a
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/InviteChoicesAlert.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/InviteChoicesAlert.java
index 9e6fca37e..5810233c3 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/InviteChoicesAlert.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/InviteChoicesAlert.java
@@ -19,14 +19,10 @@
 
 package org.eehouse.android.xw4;
 
-import android.app.Activity;
 import android.app.AlertDialog;
-import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface.OnClickListener;
 import android.content.DialogInterface;
-import android.os.Bundle;
-import android.support.v4.app.DialogFragment;
 import android.widget.Button;
 
 import java.util.ArrayList;
@@ -34,11 +30,8 @@ import java.util.List;
 
 import org.eehouse.android.xw4.DBUtils.SentInvitesInfo;
 import org.eehouse.android.xw4.DlgDelegate.Action;
-import org.eehouse.android.xw4.DlgDelegate.ActionPair;
 import org.eehouse.android.xw4.DlgDelegate.DlgClickNotify.InviteMeans;
-import org.eehouse.android.xw4.DlgDelegate.NotAgainBuilder;
 import org.eehouse.android.xw4.Perms23.Perm;
-import org.eehouse.android.xw4.loc.LocUtils;
 
 public class InviteChoicesAlert extends DlgDelegateAlert {
 
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/LookupAlert.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/LookupAlert.java
index 42cabddf0..bf4b65b7b 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/LookupAlert.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/LookupAlert.java
@@ -21,10 +21,7 @@ package org.eehouse.android.xw4;
 
 import android.app.Activity;
 import android.app.Dialog;
-import android.content.Context;
 import android.os.Bundle;
-import android.support.v4.app.DialogFragment;
-import java.io.Serializable;
 
 
 import org.eehouse.android.xw4.loc.LocUtils;
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/MainActivity.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/MainActivity.java
index 27e2da1bf..4da47abfb 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/MainActivity.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/MainActivity.java
@@ -22,12 +22,10 @@ package org.eehouse.android.xw4;
 
 import android.content.Intent;
 import android.content.res.Configuration;
-import android.graphics.Point;
-import android.graphics.Rect;
 import android.os.Bundle;
-import android.support.v4.app.DialogFragment;
-import android.support.v4.app.Fragment;
-import android.support.v4.app.FragmentManager;
+
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentManager;
 import android.text.TextUtils;
 import android.view.ContextMenu.ContextMenuInfo;
 import android.view.ContextMenu;
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/NotAgainAlert.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/NotAgainAlert.java
index 5a83acfb2..a4a49e139 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/NotAgainAlert.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/NotAgainAlert.java
@@ -19,20 +19,11 @@
 
 package org.eehouse.android.xw4;
 
-import android.app.Activity;
 import android.app.AlertDialog;
-import android.app.Dialog;
 import android.content.Context;
-import android.content.DialogInterface.OnClickListener;
-import android.content.DialogInterface;
-import android.os.Bundle;
-import android.support.v4.app.DialogFragment;
-import org.eehouse.android.xw4.DlgDelegate.Action;
+
 import org.eehouse.android.xw4.DlgDelegate.ActionPair;
 
-
-import org.eehouse.android.xw4.loc.LocUtils;
-
 public class NotAgainAlert extends DlgDelegateAlert {
     private static final String TAG = NotAgainAlert.class.getSimpleName();
 
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/OkOnlyAlert.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/OkOnlyAlert.java
index b1d00bcab..32f49f0a0 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/OkOnlyAlert.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/OkOnlyAlert.java
@@ -19,20 +19,11 @@
 
 package org.eehouse.android.xw4;
 
-import android.app.Activity;
 import android.app.AlertDialog;
-import android.app.Dialog;
 import android.content.Context;
-import android.content.DialogInterface.OnClickListener;
-import android.content.DialogInterface;
-import android.os.Bundle;
-import android.support.v4.app.DialogFragment;
-import org.eehouse.android.xw4.DlgDelegate.Action;
+
 import org.eehouse.android.xw4.DlgDelegate.ActionPair;
 
-
-import org.eehouse.android.xw4.loc.LocUtils;
-
 public class OkOnlyAlert extends DlgDelegateAlert {
     private static final String TAG = OkOnlyAlert.class.getSimpleName();
 
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/Perms23.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/Perms23.java
index 706605222..7bc525c7c 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/Perms23.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/Perms23.java
@@ -21,19 +21,15 @@ package org.eehouse.android.xw4;
 
 import android.Manifest;
 import android.app.Activity;
-import android.app.AlertDialog;
 import android.content.Context;
-import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
-import android.content.pm.PermissionInfo;
 import android.os.Build;
-import android.support.v4.app.ActivityCompat;
-import android.support.v4.content.ContextCompat;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
 
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -41,7 +37,6 @@ import java.util.Set;
 import org.eehouse.android.nbsplib.NBSProxy;
 
 import org.eehouse.android.xw4.DlgDelegate.Action;
-import org.eehouse.android.xw4.DlgDelegate.DlgClickNotify;
 import org.eehouse.android.xw4.jni.CommsAddrRec.CommsConnType;
 import org.eehouse.android.xw4.loc.LocUtils;
 
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/PrefsActivity.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/PrefsActivity.java
index 53911c4e2..ea61b4747 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/PrefsActivity.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/PrefsActivity.java
@@ -25,7 +25,6 @@ import android.app.Dialog;
 import android.content.Intent;
 import android.os.Bundle;
 import android.preference.PreferenceActivity;
-import android.support.v4.app.DialogFragment;
 
 
 import org.eehouse.android.xw4.DlgDelegate.Action;
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/RelayService.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/RelayService.java
index 78524dbb5..6eb4fb343 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/RelayService.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/RelayService.java
@@ -25,10 +25,9 @@ import android.content.Context;
 import android.content.Intent;
 import android.os.Build;
 import android.os.Handler;
-import android.support.annotation.Nullable;
+import androidx.annotation.Nullable;
 import android.text.TextUtils;
 
-import org.eehouse.android.xw4.FBMService;
 import org.eehouse.android.xw4.GameUtils.BackMoveResult;
 import org.eehouse.android.xw4.MultiService.DictFetchOwner;
 import org.eehouse.android.xw4.MultiService.MultiEvent;
@@ -58,7 +57,6 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
-import java.util.Map;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/TilePickAlert.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/TilePickAlert.java
index 54e9224d2..8313d3e85 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/TilePickAlert.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/TilePickAlert.java
@@ -25,9 +25,6 @@ import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.os.Bundle;
-import android.support.v4.app.DialogFragment;
-import android.view.View;
-import android.widget.Button;
 
 import java.io.Serializable;
 
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/Utils.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/Utils.java
index cab59e91b..c6899c6e1 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/Utils.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/Utils.java
@@ -23,12 +23,10 @@ package org.eehouse.android.xw4;
 import android.app.Activity;
 import android.app.Dialog;
 import android.app.Notification;
-import android.app.NotificationChannel;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.content.ContentResolver;
 import android.content.Context;
-import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
@@ -39,11 +37,10 @@ import android.database.Cursor;
 import android.media.Ringtone;
 import android.media.RingtoneManager;
 import android.net.Uri;
-import android.os.Build;
 import android.os.Looper;
 import android.provider.ContactsContract.PhoneLookup;
-import android.support.v4.app.NotificationCompat;
-import android.support.v4.content.FileProvider;
+import androidx.core.app.NotificationCompat;
+import androidx.core.content.FileProvider;
 import android.telephony.PhoneNumberUtils;
 import android.telephony.TelephonyManager;
 import android.text.ClipboardManager;
@@ -56,7 +53,6 @@ import android.widget.EditText;
 import android.widget.TextView;
 import android.widget.Toast;
 
-import org.json.JSONException;
 import org.json.JSONObject;
 
 import java.io.BufferedReader;
@@ -69,7 +65,6 @@ import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.Serializable;
 import java.security.MessageDigest;
-import java.util.Date;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWActivity.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWActivity.java
index a267ba61b..275de7ef7 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWActivity.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWActivity.java
@@ -23,13 +23,12 @@ package org.eehouse.android.xw4;
 import android.app.Activity;
 import android.app.Dialog;
 import android.content.Intent;
-import android.content.res.Configuration;
 import android.os.Bundle;
-import android.support.v4.app.DialogFragment;
-import android.support.v4.app.Fragment;
-import android.support.v4.app.FragmentActivity;
-import android.support.v4.app.FragmentManager;
-import android.support.v4.app.FragmentTransaction;
+import androidx.fragment.app.DialogFragment;
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentActivity;
+import androidx.fragment.app.FragmentManager;
+import androidx.fragment.app.FragmentTransaction;
 import android.view.ContextMenu.ContextMenuInfo;
 import android.view.ContextMenu;
 import android.view.Menu;
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWApp.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWApp.java
index b0d993c2a..b4f45100f 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWApp.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWApp.java
@@ -21,11 +21,11 @@
 package org.eehouse.android.xw4;
 
 import android.app.Application;
-import android.arch.lifecycle.Lifecycle;
-import android.arch.lifecycle.LifecycleObserver;
-import android.arch.lifecycle.LifecycleOwner;
-import android.arch.lifecycle.OnLifecycleEvent;
-import android.arch.lifecycle.ProcessLifecycleOwner;
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.LifecycleObserver;
+import androidx.lifecycle.LifecycleOwner;
+import androidx.lifecycle.OnLifecycleEvent;
+import androidx.lifecycle.ProcessLifecycleOwner;
 import android.content.Context;
 import android.graphics.Color;
 import android.os.Build;
@@ -39,7 +39,7 @@ import org.eehouse.android.xw4.jni.XwJNI;
 import java.util.UUID;
 
 
-import static android.arch.lifecycle.Lifecycle.Event.ON_ANY;
+import static androidx.lifecycle.Lifecycle.Event.ON_ANY;
 
 public class XWApp extends Application
     implements LifecycleObserver, NBSProxy.Callbacks {
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWDialogFragment.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWDialogFragment.java
index c83fc3de6..6de4198ef 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWDialogFragment.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWDialogFragment.java
@@ -20,10 +20,8 @@
 package org.eehouse.android.xw4;
 
 import android.app.AlertDialog;
-import android.app.Dialog;
-import android.content.Context;
 import android.content.DialogInterface;
-import android.support.v4.app.DialogFragment;
+import androidx.fragment.app.DialogFragment;
 import android.view.View.OnClickListener;
 import android.view.View;
 
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWFragment.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWFragment.java
index c0edfe1fa..750d198c4 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWFragment.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWFragment.java
@@ -20,10 +20,9 @@
 
 package org.eehouse.android.xw4;
 
-import android.app.Activity;
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.v4.app.Fragment;
+import androidx.fragment.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWJIService.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWJIService.java
index 3307c93c5..3b5e2e996 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWJIService.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/XWJIService.java
@@ -23,12 +23,11 @@ package org.eehouse.android.xw4;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.v4.app.JobIntentService;
+import androidx.core.app.JobIntentService;
 
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
-import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
diff --git a/xwords4/android/gradle.properties b/xwords4/android/gradle.properties
index 6cbe7a622..c62d03dc2 100644
--- a/xwords4/android/gradle.properties
+++ b/xwords4/android/gradle.properties
@@ -15,4 +15,7 @@ org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryErro
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
-# org.gradle.parallel=true
\ No newline at end of file
+# org.gradle.parallel=true
+
+android.useAndroidX=true
+android.enableJetifier=true