Let's do something fun! We will build a Tic-Tac-Toe game, also known as noughts and crosses, or Xs and Os.

In this game that we will build, players will choose who takes the Xs and who takes the Os. Then, they will be taking turns to mark spaces in a 3×3 grid, one mark per turn. The player who succeeds in placing three of their marks in a horizontal, vertical, or diagonal row wins the game, as shown:

In the preceding diagram, the player with Xs will have won the game because there are three crosses in a diagonal row, from the top-left corner to the bottom-right corner.

Players will have to enter their emails and names for registration to create an account before being able to start a game. They will receive a game score after each match, which is going to be added to their total score.

We will have a leaderboard that is aimed at providing information on player rankings and top scores, for a series of games played.

When creating a game, a player will have to send an invitation to another player, and then a specific waiting page will be displayed for them until another player has responded.

Following receipt of the invitation email, the other player can then confirm the request and join the game. When the two players are online, the game starts.

That is a preview of what we are going to build our demo application around, but talk is cheap. Let's get started building it up from the next section.