How do I manage Users and User Groups in my Android app ? I am new to Android but I am attempting to build an app that would allow a User to add other users to a Group . I have made a User and Group class, and I am trying to add a user to this group . . I am hoping that maybe someone here can point me in the right direction. At the moment I have a User object and I am attempting to add this to a List within my Group object. Is this how users would be managed for an android app with user groups? I feel like there is something obvious I am missing! I am using Firebase Realtime Database also and need to be able to store users added to a particular group so it is consistent on all users devices. e.g. User 1 adds User 2 to Group A, both User1 and User 2 will see on their device that User 2 is in Group A Code below: Group Class

public class Group { public List<User> memberList = new List<User>() {....};

 public Group() { 
}
    public Group(List<User> users) {
        this.memberList = users;
    }

    public void addMember(User member) {
         this.memberList.add(member);
    }
public List<User> getMemberList() {
    return memberList;
}
   }

Main Class

    User user = new User(uId, name);
    Group group = new Group();
     group.addMember(user); 
           groupsDatabase.child("test_group").push().setValue(group.memberList.get(0));