I use this website to quickly find examples of bash commands. However, it covers many programming languages and databases as well.
Explain ShellInteresting Finds
Write down a command-line to see the help text that matches each argument. `explainshell` is a tool (with a web interface) capable of parsing man pages, extracting options and explain a given command-line by matching each argument to the relevant help text in the man page.
Image to Latex formulaInteresting Finds
Recognizes mathematic formulas and converts them into LaTex format.