2. Project structure

~/Gamezone
    |-- requirements.txt
    |-- run.py
    |-- config.py
    |__ /env             # Virtual Environment
    |__ /app             # Our Application Module
         |-- __init__.py
         |__ /templates
             |-- 404.html
             |__ /auth
                 |-- signin.html
         |__ /static
         |__ /uploads
         |__ /helpers
         |__ /rest_api
         |__ /json_api
         |__ /models
         |__ /auth_api
             |-- __init__.py
             |-- auth.py
             |-- forms.py
    |__ /db
         |-- categories.py
         |-- demo_user.py

Reference: Structuring large flask applications