Adds application class.

app/src/main/AndroidManifest.xml

@@ -6,6 +6,7 @@
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
+        android:name=".MonsterCardsApplication"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">

app/src/main/java/com/majinnaibu/monstercards/MonsterCardsApplication.java

@@ -0,0 +1,44 @@
+package com.majinnaibu.monstercards;
+
+import android.app.Application;
+import android.content.Context;
+import android.content.res.Configuration;
+
+import androidx.room.Room;
+
+import com.majinnaibu.monstercards.data.MonsterRepository;
+
+public class MonsterCardsApplication extends Application {
+
+    public static MonsterCardsApplication getInstance(Context context) {
+        return (MonsterCardsApplication) context.getApplicationContext();
+    }
+
+    public MonsterCardsApplication() {
+    }
+
+
+    // Called when the application is starting, before any other application objects have been created.
+    // Overriding this method is totally optional!
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        // Required initialization logic here!
+
+    }
+
+    // Called by the system when the device configuration changes while your component is running.
+    // Overriding this method is totally optional!
+    @Override
+    public void onConfigurationChanged(Configuration newConfig) {
+        super.onConfigurationChanged(newConfig);
+    }
+
+    // This is called when the overall system is running low on memory,
+    // and would like actively running processes to tighten their belts.
+    // Overriding this method is totally optional!
+    @Override
+    public void onLowMemory() {
+        super.onLowMemory();
+    }
+}