diff --git a/android/build.gradle b/android/build.gradle
index 4fda61f..66e40db 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -2,14 +2,14 @@ group 'com.linusu.flutter_web_auth'
 version '1.0-SNAPSHOT'
 
 buildscript {
-    ext.kotlin_version = '1.3.72'
+    ext.kotlin_version = '1.5.31'
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.6.3'
+        classpath 'com.android.tools.build:gradle:7.0.3'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
@@ -17,7 +17,7 @@ buildscript {
 rootProject.allprojects {
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
 }
 
@@ -25,7 +25,7 @@ apply plugin: 'com.android.library'
 apply plugin: 'kotlin-android'
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 31
 
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
@@ -39,7 +39,7 @@ android {
     }
 
     dependencies {
-        implementation 'androidx.browser:browser:1.0.0'
+        implementation 'androidx.browser:browser:1.3.0'
     }
 }
 
diff --git a/android/gradle/wrapper/gradle-wrapper.properties b/android/gradle/wrapper/gradle-wrapper.properties
index 6623300..29e4134 100644
--- a/android/gradle/wrapper/gradle-wrapper.properties
+++ b/android/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.0.2-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/android/src/main/kotlin/com/linusu/flutter_web_auth/FlutterWebAuthPlugin.kt b/android/src/main/kotlin/com/linusu/flutter_web_auth/FlutterWebAuthPlugin.kt
index 520dcdd..b1c3d07 100644
--- a/android/src/main/kotlin/com/linusu/flutter_web_auth/FlutterWebAuthPlugin.kt
+++ b/android/src/main/kotlin/com/linusu/flutter_web_auth/FlutterWebAuthPlugin.kt
@@ -59,7 +59,7 @@ class FlutterWebAuthPlugin(private var context: Context? = null, private var cha
           }
           intent.intent.putExtra("android.support.customtabs.extra.KEEP_ALIVE", keepAliveIntent)
 
-          intent.launchUrl(context, url)
+          intent.launchUrl(context!!, url)
         }
         "cleanUpDanglingCalls" -> {
           callbacks.forEach{ (_, danglingResultCallback) ->
diff --git a/example/android/app/build.gradle b/example/android/app/build.gradle
index 1182eac..2abbdba 100644
--- a/example/android/app/build.gradle
+++ b/example/android/app/build.gradle
@@ -26,7 +26,12 @@ apply plugin: 'kotlin-android'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 31
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
 
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
@@ -40,7 +45,7 @@ android {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "com.linusu.flutter_web_auth_example"
         minSdkVersion 16
-        targetSdkVersion 28
+        targetSdkVersion 31
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -61,7 +66,7 @@ flutter {
 
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'com.android.support.test:runner:1.0.2'
-    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
+    testImplementation 'junit:junit:4.13.2'
+    androidTestImplementation 'androidx.test:runner:1.4.0'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
 }
diff --git a/example/android/app/src/main/AndroidManifest.xml b/example/android/app/src/main/AndroidManifest.xml
index 113eb6c..7e8089f 100644
--- a/example/android/app/src/main/AndroidManifest.xml
+++ b/example/android/app/src/main/AndroidManifest.xml
@@ -15,6 +15,7 @@
             android:launchMode="singleTop"
             android:theme="@style/LaunchTheme"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
+            android:exported="true"
             android:hardwareAccelerated="true"
             android:windowSoftInputMode="adjustResize">
             <!-- This keeps the window background of the activity showing
@@ -30,7 +31,9 @@
             </intent-filter>
         </activity>
 
-        <activity android:name="com.linusu.flutter_web_auth.CallbackActivity" >
+        <activity
+            android:name="com.linusu.flutter_web_auth.CallbackActivity"
+            android:exported="true">
             <intent-filter android:label="flutter_web_auth">
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />
@@ -39,5 +42,10 @@
             </intent-filter>
         </activity>
 
+        <!-- Don't delete the meta-data below.
+             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
+        <meta-data
+            android:name="flutterEmbedding"
+            android:value="2" />
     </application>
 </manifest>
diff --git a/example/android/app/src/main/kotlin/com/linusu/flutter_web_auth_example/MainActivity.kt b/example/android/app/src/main/kotlin/com/linusu/flutter_web_auth_example/MainActivity.kt
index b1be57f..feff5d3 100644
--- a/example/android/app/src/main/kotlin/com/linusu/flutter_web_auth_example/MainActivity.kt
+++ b/example/android/app/src/main/kotlin/com/linusu/flutter_web_auth_example/MainActivity.kt
@@ -1,13 +1,6 @@
 package com.linusu.flutter_web_auth_example
 
-import android.os.Bundle
-
-import io.flutter.app.FlutterActivity
-import io.flutter.plugins.GeneratedPluginRegistrant
+import io.flutter.embedding.android.FlutterActivity
 
 class MainActivity: FlutterActivity() {
-  override fun onCreate(savedInstanceState: Bundle?) {
-    super.onCreate(savedInstanceState)
-    GeneratedPluginRegistrant.registerWith(this)
-  }
 }
diff --git a/example/android/build.gradle b/example/android/build.gradle
index 45d37ba..2f2935c 100644
--- a/example/android/build.gradle
+++ b/example/android/build.gradle
@@ -1,12 +1,12 @@
 buildscript {
-    ext.kotlin_version = '1.3.72'
+    ext.kotlin_version = '1.5.31'
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.6.3'
+        classpath 'com.android.tools.build:gradle:7.0.3'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
@@ -14,7 +14,7 @@ buildscript {
 allprojects {
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
 }
 
diff --git a/example/android/gradle.properties b/example/android/gradle.properties
index a673820..94adc3a 100644
--- a/example/android/gradle.properties
+++ b/example/android/gradle.properties
@@ -1,4 +1,3 @@
 org.gradle.jvmargs=-Xmx1536M
 android.useAndroidX=true
 android.enableJetifier=true
-android.enableR8=true
diff --git a/example/android/gradle/wrapper/gradle-wrapper.properties b/example/android/gradle/wrapper/gradle-wrapper.properties
index 6623300..29e4134 100644
--- a/example/android/gradle/wrapper/gradle-wrapper.properties
+++ b/example/android/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.0.2-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/example/pubspec.lock b/example/pubspec.lock
index fc35deb..a785294 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -7,7 +7,7 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.6.1"
+    version: "2.8.1"
   boolean_selector:
     dependency: transitive
     description:
@@ -28,7 +28,7 @@ packages:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "1.3.1"
   clock:
     dependency: transitive
     description:
@@ -49,7 +49,7 @@ packages:
       name: cupertino_icons
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.2"
+    version: "1.0.3"
   fake_async:
     dependency: transitive
     description:
@@ -99,7 +99,7 @@ packages:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0"
+    version: "1.7.0"
   path:
     dependency: transitive
     description:
@@ -153,7 +153,7 @@ packages:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.0"
+    version: "0.4.2"
   typed_data:
     dependency: transitive
     description:
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index 373e2bc..88797fb 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -11,7 +11,7 @@ dependencies:
 
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
-  cupertino_icons: ^0.1.2
+  cupertino_icons: ^1.0.3
 
 dev_dependencies:
   flutter_test:
diff --git a/pubspec.lock b/pubspec.lock
index 6d552ec..d418248 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -7,7 +7,7 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.6.1"
+    version: "2.8.1"
   boolean_selector:
     dependency: transitive
     description:
@@ -28,7 +28,7 @@ packages:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "1.3.1"
   clock:
     dependency: transitive
     description:
@@ -85,7 +85,7 @@ packages:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0"
+    version: "1.7.0"
   path:
     dependency: transitive
     description:
@@ -139,7 +139,7 @@ packages:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.0"
+    version: "0.4.2"
   typed_data:
     dependency: transitive
     description: