You need the Flutter SDK installed.
Building the app is a 2-step process.
database.db is a SQLite database containing the text for the Berean Standard Bible. Build it from the database_builder project and copy the result to flutter_app/assets/database/database.db.
From the database_builder folder:
dart pub get
dart run bin/main.dart
mkdir -p ../flutter_app/assets/database
cp database.db ../flutter_app/assets/database/database.dbThe BSB Android and iOS app is built from the flutter_app folder.
From the flutter_app folder:
flutter pub get
flutter runDuring development, running the MacOS version is generally the easiest if you have a Mac.
If this is your first Flutter project, start with the online documentation.