Evernote is a multi-purpose app. First, it’s a simple tool for taking notes in a meeting or conference presentation (for example). Second, it’s a way to “clip” web pages, documents and images in much the same way as one would clip interesting articles from paper-based newspapers and magazines.
The above features are not necessarily unique. However, Evernote is downloadable to each of your devices, from phones to iPads to desktops and laptops and synchronizes across all of them, which IS unique! Essentially, this allows you to create notes on one device that, when synchronized (automatically once an internet connection is detected), becomes available across all of your devices that have Evernote. In many instances, this can eliminate the need to email documents and other information to yourself.