Calendars 5 for iPhone and iPad (App Store link), currently at version 5.2, is a very good upgrade to Readdle’s venerable Calendars+ app. Though released prior to iOS 7, the new $7 app fits right in with the newest version of iOS.
While calendar-app preferences vary widely with individual needs and circumstances, Calendars 5 has four primary strengths: It has an excellent task manager; it offers a logical, easy-to-use event-entry system; it plays well with both Google Calendar and Apple’s built-in Calendar and Reminders apps; and it sports a simple interface that’s easy on the eyes.
I’ve long been a user of Google Calendar, because I like the price, and because it’s easy to use. When you first launch Calendars 5, you’re asked if you’d like to sync it with your local (device) calendar and/or with Google. The initial sync with my Google Calendar and my local iOS Calendar was smooth and fast. (Though you initially pick either local or Google, you can add the other option later using the app’s settings screen.)
You enter events in Calendars 5 by either tapping the “+” sign in the upper-right corner of the screen, or by tapping-and-holding on a time or date on the main calendar. A pop-up box appears providing a variety of options for entering locations and notes, and to make events recurring. You can also be alerted of reminders using alert sounds, email, and SMS messages. The app remembers frequently-used locations, and it provides a list of likely candidates as you type.