<ion-header>

            <ion-navbar>
              <ion-title text-center>Jugar</ion-title>
            </ion-navbar>

          </ion-header>

          <ion-content padding>
            <div class="card">
              <div class="item item-text-wrap">
                <div class="loader">
                  <p class="percent">{{progressPercent}}segundos</p>
                </div>
              </div>
            </div>
          </ion-content>

import { Component } from '@angular/core';
          import { IonicPage, NavController, NavParams } from 'ionic-angular';

          @IonicPage()
          @Component({
            selector: 'page-jugar-online',
            templateUrl: 'jugar-online.html',
          })
          export class JugarOnlinePage {
            progressPercent;
            constructor(public navCtrl: NavController, public navParams: NavParams) {
              var count = 60;
              var intervalo = setInterval(function () {
                console.log(count);
                count--;
                this.progressPercent = count;
                if (count == 0) {
                  clearInterval(intervalo);
                  alert("Se terminó");
                }
              }, 1000);
            }

            ionViewDidLoad() {
              console.log('ionViewDidLoad JugarOnlinePage');
            }

          }