BusyCal is an excellent calendar app for Mac, and comes with a solid iOS companion app that brings the experience to mobile. BusyCal supports iCloud, Google, and other CalDAV calendar systems, and offers color-coded month, day, week, and list view of your upcoming events. Natural language parsing for event creation helps you set up appointments, with tags and a wide range of configurable attributes to get the details just right. Map support can show you an event's location and estimated travel time, and BusyCal comes with to-do list functions that are compatible with the iOS Reminders app. About the only thing we can fault is its bland but functional look.