diff --git a/enabling_splash_screen/android/build.gradle b/enabling_splash_screen/android/build.gradle
index 77cbd09..759b286 100644
--- a/enabling_splash_screen/android/build.gradle
+++ b/enabling_splash_screen/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/handling_routes/android/build.gradle b/handling_routes/android/build.gradle
index 77cbd09..759b286 100644
--- a/handling_routes/android/build.gradle
+++ b/handling_routes/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/load_local_image/android/build.gradle b/load_local_image/android/build.gradle
index 77cbd09..8da7fbe 100644
--- a/load_local_image/android/build.gradle
+++ b/load_local_image/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+       google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/load_local_json/android/build.gradle b/load_local_json/android/build.gradle
index 77cbd09..759b286 100644
--- a/load_local_json/android/build.gradle
+++ b/load_local_json/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/navigation_drawer/android/build.gradle b/navigation_drawer/android/build.gradle
index 77cbd09..759b286 100644
--- a/navigation_drawer/android/build.gradle
+++ b/navigation_drawer/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/simple_material_app/android/build.gradle b/simple_material_app/android/build.gradle
index 77cbd09..759b286 100644
--- a/simple_material_app/android/build.gradle
+++ b/simple_material_app/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/stateful_widget/android/build.gradle b/stateful_widget/android/build.gradle
index 77cbd09..759b286 100644
--- a/stateful_widget/android/build.gradle
+++ b/stateful_widget/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/stateless_widgets/android/build.gradle b/stateless_widgets/android/build.gradle
index 77cbd09..759b286 100644
--- a/stateless_widgets/android/build.gradle
+++ b/stateless_widgets/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/tip_calculator/android/build.gradle b/tip_calculator/android/build.gradle
index 77cbd09..759b286 100644
--- a/tip_calculator/android/build.gradle
+++ b/tip_calculator/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/using_alert_dialog/android/build.gradle b/using_alert_dialog/android/build.gradle
index 77cbd09..759b286 100644
--- a/using_alert_dialog/android/build.gradle
+++ b/using_alert_dialog/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/using_bottom_nav_bar/android/build.gradle b/using_bottom_nav_bar/android/build.gradle
index 77cbd09..759b286 100644
--- a/using_bottom_nav_bar/android/build.gradle
+++ b/using_bottom_nav_bar/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/using_custom_fonts/android/build.gradle b/using_custom_fonts/android/build.gradle
index 77cbd09..759b286 100644
--- a/using_custom_fonts/android/build.gradle
+++ b/using_custom_fonts/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/using_edittext/android/build.gradle b/using_edittext/android/build.gradle
index 77cbd09..759b286 100644
--- a/using_edittext/android/build.gradle
+++ b/using_edittext/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/using_gradient/android/build.gradle b/using_gradient/android/build.gradle
index 77cbd09..759b286 100644
--- a/using_gradient/android/build.gradle
+++ b/using_gradient/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/using_http_get/android/build.gradle b/using_http_get/android/build.gradle
index 77cbd09..759b286 100644
--- a/using_http_get/android/build.gradle
+++ b/using_http_get/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/using_listview/android/build.gradle b/using_listview/android/build.gradle
index 77cbd09..759b286 100644
--- a/using_listview/android/build.gradle
+++ b/using_listview/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/using_snackbar/android/build.gradle b/using_snackbar/android/build.gradle
index 77cbd09..759b286 100644
--- a/using_snackbar/android/build.gradle
+++ b/using_snackbar/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/using_stepper/android/build.gradle b/using_stepper/android/build.gradle
index 77cbd09..759b286 100644
--- a/using_stepper/android/build.gradle
+++ b/using_stepper/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/using_tabs/android/build.gradle b/using_tabs/android/build.gradle
index 77cbd09..759b286 100644
--- a/using_tabs/android/build.gradle
+++ b/using_tabs/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }
 
diff --git a/using_theme/android/build.gradle b/using_theme/android/build.gradle
index 77cbd09..759b286 100644
--- a/using_theme/android/build.gradle
+++ b/using_theme/android/build.gradle
@@ -1,22 +1,18 @@
 buildscript {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 }