Just mention the transparent theme to the starting activity in the AndroidManifest.xml file.
Like:
<activity
android:name="first Activity Name"
android:theme="@android:style/Theme.Translucent.NoTitleBar" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
and extend that screen with Activity class in place of AppCompatActivity.
like :
public class SplashScreenActivity extends Activity{
----YOUR CODE GOES HERE----
}