Create Progressive Web Apps and Offline-First Phaser games in this tutorial.
From Game Dev Academy: "Phaser is a fantastic HTML5 game framework, which can easily be run on any device. The downside is since it is an HTML5 framework, there is no out-of-the-box solution to create a mobile app version of your game. You can use other tools like PhoneGap, CocoonJS, Ionic, etc. to create a hybrid mobile app, but you are dependent on third party tools. However, if you optimize your game properly, anyone can play your game on a mobile device, but it requires the user to visit your site, and it doesn’t have some of the nice app features, like an icon on your home screen, or playing the game when you’re offline.
What if you could have a hybrid app that is a mixture of a native mobile app and a web app? Progressive Web Apps, or PWAs, feel like a native mobile app, can work offline, are responsive, and are very easy to install. Additionally, we can make our game a PWA without any third party tools. We just need to add a few files to our project, and we need to add some additional code to our main html page."