- Intro.java

public class Intro extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.intro);

        new Thread(new Runnable() {
            public void run() {
// TODO Auto-generated method stub
                try {
                    Thread.sleep(2000);
                } catch (Throwable ex) {
                    ex.printStackTrace();
                }
                Intent i = new Intent(Intro.this, MainActivity.class);
                startActivity(i);
                finish();
            }
        }).start();
    }
}

Intent i = new Intent(Intro.this, MainActivity.class); 원래 처음 로딩되는 클래스를 넣어줍니다.

- intro.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <ImageView
        android:id="@+id/intro"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:scaleType="fitXY"
        android:src="@mipmap/ic_launcher" >
    </ImageView>

</LinearLayout>

 android:src="@mipmap/ic_launcher"​ 부분은 인트로 이미지 경로를 넣습니다. 

- Manifest.xml

<activity
    android:name=".Intro"
    android:label="@string/app_name"
    android:theme="@style/Theme.AppCompat.NoActionBar">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER"/>
    </intent-filter>
</activity>

<activity
    android:name=".MainActivity"
    android:label="@string/app_name"
    android:theme="@style/Theme.AppCompat.NoActionBar">
</activity>

 웹뷰 이므로 android:theme="@style/Theme.AppCompat.NoActionBar"​ 가 추가되어있습니다. 

 MainActivity 에 해당하는 activity 가 intro activity 보다 밑에 있어야 나중에 실행이 됩니다.​