Stripo - Stripo is an all-in-one email design platform. We enable our clients to build emails of any complexity, including interactive AMP emails, really fast and easy.

Anima App - Design, get feedback, convert to code, publish, iterate.

Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.

Timeline for Sketch - Create beautiful timeline animations in Sketch

MJML - The open source framework for responsive emails

Auto-Layout for Sketch - Responsive design for Sketch