Taking part is as convenient as it gets. We built a web-based app, which can be accessed with an URL. This can then be saved to the home screen of your smartphone, so you can always easily access it anytime. Also, you always see the challenges according to your time-zone. That means, depending on the time, someone in Hawaii could still be one day behind another person opening the app in Europe. The only thing you have to think about is opening the app every day to see the daily challenges.