The Phox Water app replaces the need for physical timers which indicate when to change your water filter. Simply select which product you currently use, enter the date you replaced your latest Phox filter and let the app notify you when it is time to change your filter. Notifications will be sent when you have 5 days remaining, 4 days remaining, 1 day and when it's time to replace. The app also has a contact page that lets you quickly get in touch with a Phox representative to answer any query.