home.html

<ion-header>
  <ion-navbar>
    <ion-title>
      Ionic Twitter Firebase login
    </ion-title>
  </ion-navbar>
</ion-header>

<ion-content padding>

  <div text-center>
    <button ion-button (click)="login()">
      Login
    </button>
  </div>

  <ion-item *ngIf="user">
    <h2>{{user.displayName}}</h2>
    <ion-thumbnail item-end>
      <img src="{{user.photoURL}}">
    </ion-thumbnail>
  </ion-item>

</ion-content>