Evernote is a cross-platform, cloud-based productivity app that allows users to capture and organize notes, ideas, tasks, and more. It offers a variety of features, including the ability to take notes in a variety of formats (text, audio, images, etc.), create notebooks for organizing notes, and access notes from any device with an internet connection. Evernote also integrates with a wide range of other apps and services, making it easy to use in conjunction with other tools. It is designed to help users streamline their workflow and increase productivity.