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.
Git analytics - for software developers, teams, and open-source communities
Ruby Toolbox - Explore and compare open source Ruby libraries
Good First Issue - Make your first open-source contribution
GitNews Web - Trending repositories from GitHub, HackerNews & Reddit
GitSheet - A dead simple Git cheat sheet.