diff --git a/IAP5Helper/build.gradle b/IAP5Helper/build.gradle
index 333d65e..4febbb5 100644
--- a/IAP5Helper/build.gradle
+++ b/IAP5Helper/build.gradle
@@ -1,7 +1,7 @@
 apply plugin: 'com.android.library'
 android {
     compileSdkVersion 28
-    buildToolsVersion '28.0.2'
+    buildToolsVersion '28.0.3'
 
     defaultConfig {
         minSdkVersion 14
diff --git a/app/build.gradle b/app/build.gradle
index 2a06d20..2e5acd3 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -44,10 +44,14 @@ android {
         }
     }
     buildTypes {
+        debug {
+            resValue "string", "adbmob_ad_unit_id", "ca-app-pub-3940256099942544/6300978111"
+        }
         release {
             minifyEnabled true
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
             signingConfig signingConfigs.release
+            resValue "string", "adbmob_ad_unit_id", "ca-app-pub-3319579963502409/4464724664"
         }
     }
     flavorDimensions "platform"
@@ -98,5 +102,10 @@ dependencies {
     implementation 'io.reactivex.rxjava2:rxandroid:2.1.0'
     implementation 'io.reactivex.rxjava2:rxjava:2.2.6'
     implementation "ch.acra:acra-http:$acraVersion"
+    implementation 'com.google.firebase:firebase-core:16.0.7'
+    implementation 'com.google.firebase:firebase-ads:17.1.3'
+    implementation 'com.android.billingclient:billing:1.2'
     samsungImplementation project(":IAP5Helper")
 }
+
+apply plugin: 'com.google.gms.google-services'
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 84b1d32..5ab0178 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -17,6 +17,10 @@
         android:theme="@style/AppTheme"
         tools:ignore="AllowBackup"
         tools:targetApi="n">
+        <meta-data
+            android:name="com.google.android.gms.ads.APPLICATION_ID"
+            android:value="@string/admob_app_id" />
+
         <activity
             android:name=".view.activity.SplashActivity"
             android:theme="@style/AppTheme.Splash"
diff --git a/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MainActivity.java b/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MainActivity.java
index 7cb50ac..20cce41 100644
--- a/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MainActivity.java
+++ b/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MainActivity.java
@@ -16,6 +16,11 @@ import android.view.MenuItem;
 import android.view.View;
 import android.widget.Toast;
 
+import com.google.ads.mediation.admob.AdMobAdapter;
+import com.google.android.gms.ads.AdListener;
+import com.google.android.gms.ads.AdRequest;
+import com.google.android.gms.ads.AdView;
+import com.google.android.gms.ads.MobileAds;
 import com.wbrawner.simplemarkdown.MarkdownApplication;
 import com.wbrawner.simplemarkdown.R;
 import com.wbrawner.simplemarkdown.presentation.MarkdownPresenter;
@@ -44,6 +49,8 @@ public class MainActivity extends AppCompatActivity
     DisableableViewPager pager;
     @BindView(R.id.layout_tab)
     TabLayout tabLayout;
+    @BindView(R.id.adView)
+    AdView adView;
 
     private boolean shouldAutoSave = true;
     private NewFileHandler newFileHandler;
@@ -68,6 +75,25 @@ public class MainActivity extends AppCompatActivity
         if (getIntent().getBooleanExtra(Constants.EXTRA_EXPLORER, false)) {
             requestFileOp(Constants.REQUEST_OPEN_FILE);
         }
+
+        // TODO: Change this to only load for users who haven't paid to remove ads
+        if (true) {
+            MobileAds.initialize(this, getString(R.string.admob_app_id));
+            Bundle extras = new Bundle();
+            extras.putString("npa", "1");
+            AdRequest adRequest = new AdRequest.Builder()
+                    .addTestDevice("7045AFE2F8D6C6386983BAF3D2A2377E")
+                    .addNetworkExtrasBundle(AdMobAdapter.class, extras)
+                    .build();
+            adView.setAdListener(new AdListener() {
+                @Override
+                public void onAdFailedToLoad(int i) {
+                    super.onAdFailedToLoad(i);
+                    ACRA.getErrorReporter().handleException(new RuntimeException("Failed to load ads: " + i), false);
+                }
+            });
+            adView.loadAd(adRequest);
+        }
     }
 
     @Override
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index eb02df8..3457501 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -1,13 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
-<LinearLayout
-    xmlns:android="http://schemas.android.com/apk/res/android"
+<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
 
     <com.wbrawner.simplemarkdown.view.DisableableViewPager
         android:id="@+id/pager"
         android:layout_width="match_parent"
-        android:layout_height="match_parent">
+        android:layout_height="0dp"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintBottom_toTopOf="@+id/adView">
         <android.support.design.widget.TabLayout
             android:id="@+id/layout_tab"
             android:layout_width="match_parent"
@@ -26,4 +30,15 @@
         </android.support.design.widget.TabLayout>
     </com.wbrawner.simplemarkdown.view.DisableableViewPager>
 
-</LinearLayout>
+    <com.google.android.gms.ads.AdView xmlns:ads="http://schemas.android.com/apk/res-auto"
+        android:id="@+id/adView"
+        android:layout_width="wrap_content"
+        android:layout_height="50dp"
+        ads:adSize="SMART_BANNER"
+        ads:adUnitId="@string/adbmob_ad_unit_id"
+        app:layout_constraintTop_toBottomOf="@+id/pager"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintBottom_toBottomOf="parent"></com.google.android.gms.ads.AdView>
+
+</android.support.constraint.ConstraintLayout>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 6522f5e..7827f1e 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1,6 +1,9 @@
 <resources xmlns:tools="http://schemas.android.com/tools"  tools:ignore="MissingTranslation">
     <string name="app_name">Simple Markdown</string>
     <string name="app_name_short">Markdown</string>
+
+    <string name="admob_app_id">ca-app-pub-3319579963502409~4576405307</string>
+
     <string name="action_settings">Settings</string>
     <string name="action_help">Help</string>
     <string name="action_edit">Edit</string>
diff --git a/build.gradle b/build.gradle
index 8553826..50c26da 100644
--- a/build.gradle
+++ b/build.gradle
@@ -7,8 +7,7 @@ buildscript {
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:3.3.1'
-        // NOTE: Do not place your application dependencies here; they belong
-        // in the individual module build.gradle files
+        classpath 'com.google.gms:google-services:4.2.0'
     }
 }