Mailbox is a freeware email management application for iOS, Android, and OS X developed by Orchestra, Inc. The application received coverage on numerous technology blogs for its ease-of-use and innovative features, including swipe-based email sorting and filtering.Weeks before its launch, pre-registration prompted a wait list of over 380,000. Mailbox was added to the iOS App Store on Thursday, February 7, 2013; it became the second most downloaded free app in the App Store that day.