help..!!!
The results of the build of the App Inventor APK cannot be opened on the cellphone, only a white screen
You need to provide your aia project, or screenshots of the relevant blocks initialised on startup.
Also might help to know, number of screens, number of blocks for each screen, size of assets.
Upload your app to https://unchive.kodular.io to get some statistics of your project and post the statistics overview
Taifun