The Postmark iOS app provides a mobile version of their email monitoring and troubleshooting tools, allowing users to investigate and resolve delivery issues on-the-go. The initial release focuses on core tools for managing transactional email, including searching messages, viewing details, monitoring volume and bounce stats, investigating bounced emails, and more. The app is designed to be secure with features like Touch ID or Face ID, and it will continue to evolve with future releases. It is currently available for Apple devices running iOS 11 or later, requiring a Postmark account with owner or admin permissions.