Refined Twitter - A browser extension that improves the Twitter experience
Email Inspire - Discover the best of email design and marketing — Browse email newsletters from top brands.
Typefully - Write & publish great tweets, without distractions
EmailWay - Collection of the most insightful and informative email newsletters from across a wide spectrum of industries and interests
Tweet Tray - Tweet quickly from your desktop without any distractions.
Really Good Emails - A large collection of good product email design.