input: Write a function to create a Flask application that submits form data (Name, Email, Phone) and stores it in a SQLite database. The function should return the Flask app instance.
  
  from flask import Flask, render_template, request, redirect
  import sqlite3
  
  def create_flask_app():
      app = Flask(__name__)
  
      @app.route('/')
      def home():
          return render_template('index.html')
  
      @app.route('/submit', methods=['POST'])
      def submit():
          name = request.form.get('name')
          email = request.form.get('email')
          phone = request.form.get('phone')
          
          conn = sqlite3.connect('data.db')
          cur = conn.cursor()
          
          cur.execute("INSERT INTO data (name, email, phone) VALUES (?, ?, ?)", (name, email, phone))
          conn.commit()
          
          return redirect('/')
      
      if __name__ == '__main__':
          app.run(debug=True)
      
      return app
  
  assert create_flask_app() is not None
output: 
  def create_flask_app():
      app = Flask(__name__)
  
      @app.route('/')
      def home():
          return render_template('index.html')
  
      @app.route('/submit', methods=['POST'])
      def submit():
          name = request.form.get('name')
          email = request.form.get('email')
          phone = request.form.get('phone')
          
          conn = sqlite3.connect('data.db')
          cur = conn.cursor()
          
          cur.execute("INSERT INTO data (name, email, phone) VALUES (?, ?, ?)", (name, email, phone))
          conn.commit()
          
          return redirect('/')
      
      if __name__ == '__main__':
          app.run(debug=True)
      
      return app
  