Polymail - Native email app for email productivity.
Affinity - Relationship Intelligence, Reimagined
Airmail - Airmail is a lightweight and lightning fast mail client for Mac.
Zapflow - Zapflow is a cloud-based tool for professional investors to manage their deal flows.
Morning Mail - A new way to manage your mail. Tinder for email.
Pipedrive - Sales pipeline software that gets you organized. Helps you focus on the right deals, so easy to use that salespeople just love it. Great for small teams.