Canary Mail - Privacy-aware email app for Mac & iOS
Handwrytten - Handwritten notes straight from your device. Huge selection of cards or design your own. Handwriting service integrates with 1000's of apps.
Flow-e - Turn your Gmail or Office365 inbox to a Visual Task Board.
Felt for iPhone - Handwritten cards for the modern world
Airmail - Airmail is a lightweight and lightning fast mail client for Mac.
Inkpact - Send genuine handwritten messages in just a few clicks