Awesome Cal - Awesome Cal is a Calendar application for your iPhone that you can take anywhere and keep close by to monitor all the upcoming birthdays, festivities, meetings, and more from a single place.

Sectograph - Sectograph app enables you to create a visual event tracker to keep track of all your upcoming events and due tasks right from the home screen.

Pocket Informant - Pocket Informant is the Best Calendar app for mac and iOS. Pocket Informant for iOS, Mac desktop, and Android.

Power Planner - Record homework and class schedule.

Fantastical 2 - Fantastical, the Mac calendar app you'll enjoy using. Quickly create new events with natural language input and more.

Dreamie Planner - Dreamie Planner app contains a built-in diary through which users can write important details about their daily tasks and can send the content of the diary to their friends and colleagues.