Added strings to strings.xml, Added a TextView to the layout.xml and changed the color of the button on press.

app/src/main/java/com/MartyrPher/smapiandroidinstaller/MainActivity.java

@@ -30,6 +30,8 @@ public class MainActivity extends AppCompatActivity {
         start_button.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
+                start_button.setBackgroundColor(getResources().getColor(R.color.colorAccent));
+                Toast.makeText(MainActivity.this, R.string.start_install, Toast.LENGTH_SHORT).show();
                 if (hasPermissions)
                 {
                     boolean foundGame;
@@ -39,9 +41,14 @@ public class MainActivity extends AppCompatActivity {
                     foundGame = apkExtractor.extractAPK(getApplicationContext());
 
                     if(foundGame)
+                    {
                         backgroundTask.execute();
+                    }
                     else
+                    {
                         DialogFrag.showDialog(MainActivity.this, R.string.cant_find, 1);
+                        start_button.setBackgroundColor(getResources().getColor(R.color.colorPrimary));
+                    }
 
                 }
                 else
@@ -74,7 +81,7 @@ public class MainActivity extends AppCompatActivity {
                 if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
                 {
                     hasPermissions = true;
-                    Toast.makeText(this, "Permission Granted :)", Toast.LENGTH_SHORT).show();
+                    Toast.makeText(this, R.string.permission, Toast.LENGTH_SHORT).show();
                 }
                 break;
         }

app/src/main/res/layout/activity_main.xml

@@ -13,14 +13,29 @@
         android:layout_marginStart="8dp"
         android:layout_marginTop="8dp"
         android:layout_marginEnd="8dp"
-        android:layout_marginBottom="8dp"
 
+        android:layout_marginBottom="8dp"
         android:background="@color/colorPrimary"
         android:text="Install"
         android:textColor="@android:color/white"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/textView" />
+
+    <TextView
+        android:id="@+id/textView"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="8dp"
+        android:layout_marginTop="64dp"
+        android:layout_marginEnd="8dp"
+        android:text="Notes: Game version 1.25 is required"
+        android:textColor="@android:color/black"
+        android:textSize="18sp"
+        android:textStyle="bold"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent" />
 
 </android.support.constraint.ConstraintLayout>

app/src/main/res/values/strings.xml

@@ -4,4 +4,6 @@
     <string name="modify_apk">Modifying the Apk…this might take some time. Please keep the screen on.</string>
     <string name="finished">Finished!</string>
     <string name="install">Error in opening file!</string>
+    <string name="start_install">Starting Install</string>
+    <string name="permission">Permission Granted</string>
 </resources>