Free. Current App Store rating: 4.5 stars
No discussion of mediocre native iOS apps would be complete without throwing shade on Apple's iOS 7 Calendar app. We could write an entire slideshow on that app's failure, but instead let's focus on the alternative Sunrise Calendar. It's compatible with only Google Calendar and iCloud, unfortunately. But it integrates nicely with Facebook, Twitter, Foursquare, LinkedIn and Google Maps. If you have an appointment with someone you're connected to on LinkedIn, for example, Sunrise shows his LinkedIn profile pic. And if your appointment is offsite, you can check driving directions via Google Maps. Tempo Smart Calendar and 24me are two more free and compelling Calendar alternatives.