Sometimes, a pretty and simple design can work against you. Take, for example, Peek Calendar. Meant to be used with one hand, a series of swipes and gestures is all you need to quickly navigate your agenda. The design aesthetic is similar to that of the popular to-do list app Clear, using bars that elegantly swipe to the side and fold-open to give you more information.
On first blush, the app looks and feels intuitive, but after spending some time with it you'll see that it's missing some key features that every calendar app should have. According to the developers, some of those are yet to come, but until they arrive it's not worth a download.
Getting started with Peek
When you first launch the app after installation, you're prompted to grant access to the events stored in your Calendar app. Then, after you're set up, each day for the current week is represented with a colored bar. Tapping on it will unfold the day's activities. You can view the duration and location of each respective activity by swiping the title bar to the right. A swipe to the left opens a menu where you'll find reminders of the most common navigation methods used in the app, along with a video tutorial, and the app settings. Scrolling past the week view will bring up a month view, where you can then view past and upcoming events by tapping on the date.
In the settings section, you can change the color theme, toggle the app sounds and vibration, set the first day of the week (to either Sunday or Monday), and toggle a feature that displays the current time when the proximity sensor is covered. I recommend turning this last feature off, as it repeatedly activated itself while trying to view my agenda even if the sensor wasn't being covered.
Some gestures and navigation that Peek Calendar uses are intuitive; others are not. For example, entering the start and end times for an appointment requires you to tap and hold on the time field, before using sliders to set the proper time. It seems like it would be easier if you could tap on the screen and edit the time directly. Too avoid frustration with the app's many interface quirks, I strongly advise you to view the tutorial page linked to in the app's menu before you start entering events.