controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'VisitDays'
});

models.user.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  firstName: attr("string"),
  lastName: attr("string"),
  visits: belongsTo("visit")
});

models.visit.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  name: attr("string"),
  users: hasMany("user"),
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  beforeModel() {
    var user1 = this.store.createRecord("user", {
      id: 1,
      firstName: "First",
      lastName: "User",
    });
    
		var user2 = this.store.createRecord("user", {
      id: 2,
      firstName: "Second",
      lastName: "User",
    });
    
   	var user3 = this.store.createRecord("user", {
      id: 3,
      firstName: "Third",
      lastName: "User",
    });
    
		var user4 = this.store.createRecord("user", {
      id: 4,
      firstName: "Fourth",
      lastName: "User",
    });
    
    var user5 = this.store.createRecord("user", {
      id: 5,
      firstName: "Fifth",
      lastName: "User",
    });
    
    var visit1 = this.store.createRecord("visit", {
      id: 1,
      name: "Morning Visit",
      users: [user1, user2, user3]
    });
    
    var visit2 = this.store.createRecord("visit", {
      id: 2,
      name: "Afternoon Visit",
      users: [user4, user5]
    });

    var visit3 = this.store.createRecord("visit", {
      id: 3,
      name: "Afternoon Visit No One Attending",
      users: []
    });
  },

});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
{{outlet}}

twiddle.json

{
  "version": "0.10.5",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-data": "2.12.1",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {}
}