Distill - Tracking website updates, automated and simplified
GrowthList - A crowd-sourced list of growth hacks
Reddit Check - A tool to check if a URL is on Reddit and going viral
GrowthHackers Projects - Growth collaboration software for teams 📈
FeedMail - FeedMail sends you updates from your favourite websites directly to your inbox (or filed nicely into a label of your choice).
Marketing Examples - A gallery of real world marketing case studies. Updated every day.