HTMLEmail.io - Responsive HTML email templates for startups & developers
LogTailApp - LogTail is a local and remote (SSH) log file viewer and monitoring application for Mac OS X. It is a pure, modern, document-based Cocoa App
Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.
Hawk - Hawk provides visual user tracking and error reporting with live screen view, deep filtering and robust access control.
MJML - The open source framework for responsive emails
AppSignal - We monitor the software that makes your customers happy.