GitSpo - Measure & engage your open-source community
GitSheet - A dead simple Git cheat sheet.
Devo - Devo delivers real-time operational & business value from analytics on streaming and historical data to operations.
AI Cheatsheet - A tool to help you ace AI basics
LibHunt - LibHunt tracks mentions of software libraries on relevant social networks. Based on that data, you can find the most popular projects and their alternatives.
Code House - A whole new world of 300+ developer cheat-sheets