Moodle Mobile is the Moodle official mobile application for Android, iOS, and Windows Phone. It is available in Google Play, Apple Market, and Windows App Stores. The app requires Moodle versions 2.4 and later.
To enable access of your site through mobile app, log in as the administrator and navigate to:
Site administration → Plugins → Web services → Mobile
Tick the 'Enable web services for mobile devices' checkbox, then click save changes button.