fzf is a “general-purpose command-line fuzzy finder” written in Go. It’s very fast, has a vim plugin and is useful for custom interface commands.

I don’t make extensive use of it yet, but a quick (and dirty) example for how I use it is my function to quickly access my notes from the command line:

nvim + (find ~/notes -name "*.md" | fzf)

This just throws the note I’m looking for into neovim.