How To fix white screen on app Start up?

Put this in a custom style and it solves all the problems. Using the hacky translucent fix will make your task bar and nav bar translucent and make the splashscreen or main screen look like spaghetti.

<item name="android:windowDisablePreview">true</item>

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----
}