On your mobile phone run your browser often called Internet or Web and enter the web app address:
As a technologist I have to praise the JP branch for creating a web app that works on all devices rather than the shortsighted route of creating native apps for Android, Apple, Windows Phone and so on, each of which has to be downloaded and updated separately. With a web app you always see the latest version and the app developers only need to work on one version.
Some other screens in the app to whet your appetite:
Well done JP branch.