Reminders will notify you that it's time to Flip Off your phone. You can customize your reminders depending on your level (free or premium). Free users can create 1 custom reminder to Flip Off which they can set to any time, recurring daily. Premium users can create a schedule of an unlimited number of reminders set to any time, recurring any day of the week.
Why am I not getting my reminders? You may not have enabled Flipd notifications. Go to your device Settings > Apps > Flipd and then enable push notifications.