This must be tested in a site with the feedback WebServices integrated. Use course "Different types of feedback" to test this issue. Create some groups and configure one feedback with visible groups and one with separated groups. In the app, check that you can open the feedback. All the buttons will take you to the web site. As a teacher check you see the feedback overview including group parameters, number of the feedback questions and number of submitted responses, opening and closing time... Also you will see a preview button if there's any question. As a student check you see the feedback properties (opened or not, mode and if you answered the feedback). Also you will see a preview and answer the questions buttons if there's any question and the user can answer the activity. Check you can prefetch the module on both roles.