This app was made using React for frontend and Express and MongoDB for backend. The backend part of the app is located here. If you want to try out the app, you can do it here.

Here are some pictures from the app:

Users can get to this page only if they are not logged in.
If they enter a valid combination of a username and password the user will login into his accout

Users can get to this page only if they are not logged in.
If they enter a username which hasn't been taken yet and a valid password they will create new accouts

The login system was made using passportJS and JWT, each time a user logs into an account a JWT is stored in their browser. This JWT makes the session possible and its available 12 hours or until the user logs out