personal-toolbox
Can I Use: Browser support charts for that new hip web technology that you want to use. Includes very basic geographic reports.
Mozilla Developer Network Web Docs: Great for assessing the real world implications of various web elements down to the CSS selector and/or HTML tag level.
HTTP Statuses: Beautiful references for each and every HTTP status. It isn't a reproduction of the specs.
Ruby Toolbox: Meta-tool for the Ruby world.
dply: Free servers with 2h lifespan.
explainshell.com: Parses real shell commands and explains each option
ngrok: Expose a local (dev) server to the Internet. Even behind a firewall.
BlackBox: Store secrets securely in git repos.
jq: Parse and process JSON in the command line
Read-O-meter: Calculates reading time for articles
repl.it: Online REPL interpreter for lots of programming languages
patch-package: Do not wait for your PRs to get merged. Works on the npm ecosystem.
star-history: View history of github stars. Good for evaluating tendencies.
the noun project: "Toilet people" icon library
ponyfoo: Good articles about JS (maybe about other subjects too)
slate: Markdown-based static site generator for API documentation
carbon: Turn source code into a nice image
silicon: carbon, but offline. written in Rust :-)