It was asked in the App Inventor Forum, black screen during 2 seconds at launch application.
Necessary folders/files can be downloaded from here.
If you’ve made an app and then realized that you would like a splash screen for your app
or that it’s a heavy app and causes black screen during start.
Then this may be the solution for you.
Icon: your icon image that we will use for the backrund image during launch of the app (icon size 144px)
and that’s all in MIT AI2, download and save your project.apk in ..AppToMarket_v41\myApks\ folder.
Launch your AppToMarket and browse for your project.
Features & Update Manifest
Select necessary features and update Manifest
Slider: Set it to Any
You’ll have to add/replace
android:theme="@style/Theme.BaasTheme" manually in the manifest file.
and the last thing before you click the Create New.apk button
copy downloaded folders/files to …AppToMarket_v41\temp_myDecompiles\res\ folder