As a calendar app, the Sunrise Calendar is quite a looker. Furthermore, it supports both the Google calendar and the iCloud calendar. It also does pretty well as far as iCloud event sharing is concerned. This one is definitely a solid choice if you want an app to integrate all your calendar events efficiently.
Sunrise App for Adults with ADHD: "Stay on schedule and be where you need to be, when you need to be there with Sunrise, a calendar app that syncs with your Google calendar and interfaces with Facebook, Evernote, and more so that you have everything you need to do in one, easy to view place."