We have been using extensions to amplify our examples for a few chapters now; Flask-SQLAlchemy was used to connect to a relational database, Flask-MongoEngine to connect to MongoDB, Flask-WTF to create flexible reusable forms, and so on. Extensions are a great way to add functionality to your projects without adding anything in the way of your code and, if you like what we've done so far, you're going to love this chapter because it is dedicated to extensions!

In this chapter, we'll learn about a few very popular extensions we have neglected so far. Shall we begin?