Connect More
https://connectmore.bytesizedben.com/
An online version of Connect 4 that allows more then two people to play at once. You can also customize your board size and how many pieces you need in a row to win.
To play, simply enter a user name, then create a lobby. You can now copy the lobby's link or scan the QR code, to open it up on another device. It's designed to adapt to both phone and desktop.