diff --git a/build.gradle b/build.gradle
index d961204..25dc8e2 100644
--- a/build.gradle
+++ b/build.gradle
@@ -2,11 +2,10 @@
 buildscript {
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
     dependencies {
-        //classpath "com.android.tools.build:gradle:4.1.1"
-        classpath 'com.android.tools.build:gradle:3.5.0'
+        classpath 'com.android.tools.build:gradle:7.0.4'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -28,7 +27,7 @@ allprojects {
     repositories {
         maven { url 'https://jitpack.io' }
         google()
-        jcenter()
+        mavenCentral()
     }
     gradle.projectsEvaluated {
         tasks.withType(JavaCompile) {
diff --git a/codec2talkie/build.gradle b/codec2talkie/build.gradle
index bd18730..a338e0c 100644
--- a/codec2talkie/build.gradle
+++ b/codec2talkie/build.gradle
@@ -4,13 +4,13 @@ plugins {
 
 android {
     android.ndkVersion "21.4.7075529"
-    compileSdkVersion 30
-    buildToolsVersion "30.0.2"
+    compileSdkVersion 31
+    buildToolsVersion "31.0.0"
 
     defaultConfig {
         applicationId "com.radio.codec2talkie"
         minSdkVersion 23
-        targetSdkVersion 30
+        targetSdkVersion 31
         versionCode 172
         versionName "1.72"
 
diff --git a/codec2talkie/src/main/AndroidManifest.xml b/codec2talkie/src/main/AndroidManifest.xml
index d378d9d..cebf84f 100644
--- a/codec2talkie/src/main/AndroidManifest.xml
+++ b/codec2talkie/src/main/AndroidManifest.xml
@@ -30,39 +30,51 @@
         <service android:name=".app.AppService"
             android:foregroundServiceType="location|microphone"/>
         <activity
+            android:exported="false"
             android:name=".connect.UsbConnectActivity"
             android:configChanges="orientation|screenSize" />
         <activity
+            android:exported="false"
             android:name=".connect.TcpIpConnectActivity"
             android:configChanges="orientation|screenSize" />
         <activity
+            android:exported="false"
             android:name=".connect.BluetoothConnectActivity"
             android:configChanges="orientation|screenSize"/>
         <activity
+            android:exported="false"
             android:name=".connect.BleConnectActivity"
             android:configChanges="orientation|screenSize"/>
         <activity
+            android:exported="false"
             android:name=".settings.BluetoothSettingsActivity"
             android:configChanges="orientation|screenSize" />
         <activity
+            android:exported="false"
             android:name=".settings.AprsSymbolSelectionActivity"
             android:configChanges="orientation|screenSize" />
         <activity
+            android:exported="false"
             android:name=".recorder.RecorderActivity"
             android:configChanges="orientation|screenSize" />
         <activity
+            android:exported="false"
             android:name=".storage.log.LogItemActivity"
             android:configChanges="orientation|screenSize" />
         <activity
+            android:exported="false"
             android:name=".storage.message.group.MessageGroupActivity"
             android:configChanges="orientation|screenSize" />
         <activity
+            android:exported="false"
             android:name=".storage.message.MessageItemActivity"
             android:configChanges="orientation|screenSize" />
         <activity
+            android:exported="false"
             android:name=".maps.MapActivity"
             android:configChanges="orientation|screenSize" />
         <activity
+            android:exported="false"
             android:name=".MainActivity"
             android:configChanges="orientation|screenSize">
             <intent-filter>
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 32a3354..1e8173b 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.5-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.0.2-bin.zip
diff --git a/libcodec2-android/build.gradle b/libcodec2-android/build.gradle
index 6971005..ef33b76 100644
--- a/libcodec2-android/build.gradle
+++ b/libcodec2-android/build.gradle
@@ -3,7 +3,7 @@ apply plugin: 'com.android.library'
 
 buildscript {
     repositories {
-        jcenter()
+        mavenCentral()
     }
 
     dependencies {
@@ -12,7 +12,7 @@ buildscript {
 }
 
 android {
-    compileSdkVersion 30
+    compileSdkVersion 31
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
@@ -21,9 +21,7 @@ android {
 
     defaultConfig {
         minSdkVersion 16
-        targetSdkVersion 30
-        versionCode 1
-        versionName "1.0"
+        targetSdkVersion 31
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
         externalNativeBuild {
             cmake {
@@ -46,11 +44,6 @@ android {
             path "src/main/cpp/CMakeLists.txt"
         }
     }
-    sourceSets {
-        main {
-            jniLibs.srcDirs = ['build/imported-lib']
-        }
-    }
 }
 
 // As per: https://github.com/googlesamples/android-ndk/blob/master/hello-libs/app/build.gradle
@@ -110,7 +103,7 @@ task compileCodec2 {
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation 'com.android.support:support-annotations:28.0.0'
-    testImplementation 'junit:junit:4.12'
+    testImplementation 'junit:junit:4.13.1'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
 }
diff --git a/libopus-android/build.gradle b/libopus-android/build.gradle
index a2987c2..a65fc57 100644
--- a/libopus-android/build.gradle
+++ b/libopus-android/build.gradle
@@ -3,7 +3,7 @@ apply plugin: 'com.android.library'
 
 buildscript {
     repositories {
-        jcenter()
+        mavenCentral()
     }
 
     dependencies {
@@ -12,7 +12,7 @@ buildscript {
 }
 
 android {
-    compileSdkVersion 30
+    compileSdkVersion 31
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
@@ -21,9 +21,7 @@ android {
 
     defaultConfig {
         minSdkVersion 16
-        targetSdkVersion 30
-        versionCode 1
-        versionName "1.0"
+        targetSdkVersion 31
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
         externalNativeBuild {
             cmake {
@@ -46,11 +44,6 @@ android {
             path "src/main/cpp/CMakeLists.txt"
         }
     }
-    sourceSets {
-        main {
-            jniLibs.srcDirs = ['build/imported-lib']
-        }
-    }
 }
 
 // As per: https://github.com/googlesamples/android-ndk/blob/master/hello-libs/app/build.gradle
@@ -109,7 +102,7 @@ task compileOpus {
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation 'com.android.support:support-annotations:28.0.0'
-    testImplementation 'junit:junit:4.12'
+    testImplementation 'junit:junit:4.13.1'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
 }