blank screen comes before splash

Generally speaking, splash screens are not recommended for an app but if you really must.

Android will load a blank layout before it loads an activity layout based on the theme you have set for it. The solution is to set the theme of the splash activity to a transparent one.

Create a transparent theme in res/values/styles.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
   <style name="Theme.Transparent" parent="android:Theme">
      <item name="android:windowIsTranslucent">true</item>
      <item name="android:windowBackground">@android:color/transparent</item>
      <item name="android:windowContentOverlay">@null</item>
      <item name="android:windowNoTitle">true</item>
      <item name="android:windowIsFloating">true</item>
     <item name="android:backgroundDimEnabled">false</item>
  </style>
</resources>

Then set the theme in your manifest

<activity android:name=".SplashActivity" android:theme="@style/Theme.Transparent">
...
</activity>