This Retina display-optimized app provides a front face for accessing Evernote's popular note-taking and storage service. While the app's design lacks some finesse, it does simplify note-taking, capturing quick tasks and saving documents as Web pages. The process of searching through notes is now simplified, so all you need to do is tell it what you want in plain language — for instance, you can tell the app you want to search for "notes with PDF." All of this info is then synced to the cloud, so all of your devices have access to the same data. Step up to the premium version to add annotations and markup ($45 per year). If you're stuck in the Microsoft camp, the company's OneNote software offers similar functionality, also for free.