A fantastic and comprehensive tutorial on creating multiplayer games with PubNub and Phaser.
Over on the PubNub site Ninja Pig Studios have posted a comprehensive tutorial on creating a multiplayer game with Phaser and PubNub lite (their free tier).
The tutorial is superb and covers everything from setting up your local environment, to player movement and using the PubNub API. You can test it by opening 2 browser windows side-by-side or using devices to play from, and the code is free on GitHub.
There are lots of competing 'realtime' services out there, and with IO games becoming so popular I think we're only going to see more of them emerge. If they all have tutorials as comprehensive as this one we're in for a fun time!