text: from flask import Flask
  from config import config_options
  from flask_sqlalchemy import SQLAlchemy
  from flask_bootstrap import Bootstrap
  from flask_login import LoginManager
  from flask_mail import Mail
  
  #create instances
  db = SQLAlchemy()
  bootstrap = Bootstrap()
  mail = Mail()
  
  #login Extensions
  login_manager = LoginManager()
  login_manager.session_protection = 'strong'
  login_manager.login_view = 'auth.login'
  
  def create_app(config_name):
     app = Flask(__name__)   
     
     #create app configurations
     app.config.from_object(config_options[config_name])
     
     # Initializing flask extensions
     db.init_app(app)
     bootstrap.init_app(app)
     login_manager.init_app(app)
     mail.init_app(app)   
     
     #Register the blueprints
     from .main import main as main_blueprint 
     app.register_blueprint(main_blueprint)
     
     from .auth import auth as auth_blueprint
     app.register_blueprint(auth_blueprint,url_prefix = '/authenticate')
     
     return app