Superhuman Mail is an iPhone application developed by SUPERHUMAN LABS INC. It is a free productivity application that aims to revolutionize the email experience. The app boasts of being twice as fast as traditional email clients and is packed with features that help users manage their inbox efficiently.

One of the standout features of Superhuman Mail is Social Insights. This feature provides context from LinkedIn, Facebook, Twitter, and more, allowing users to be brilliant with people. Another impressive feature is the Undo Send function, which helps users work faster and with more confidence than before. The Split Inbox feature allows users to respond faster to the people who need them, while the Reminders feature ensures that users follow up on time, every time.

Superhuman Mail also offers a Send Later function, allowing users to send emails at the perfect moment. The Snooze feature helps users focus on what matters by clearing their inbox and enjoying a more productive workspace. Additionally, the app works offline, ensuring that users can be productive anywhere.

Overall, Superhuman Mail is an excellent email client that offers a range of productivity features designed to make email management faster and more efficient.