Powerline is a statusline plugin for vim, and provides statuslines and prompts for several other applications, including zsh, bash, fish, tmux, IPython, Awesome, i3 and Qtile.

Powerline @ GitHub

The minimal, blazing-fast, and infinitely customizable prompt for any shell!

Starship Prompt @ GitHub

Cod is a completion daemon for {bash,fish,zsh}.
It detects usage of --help commands parses their output and generates auto-completions for your shell.

A package manager for shell scripts and functions.

Basher allows you to quickly install shell packages directly from github (or other sites). Instead of looking for specific install instructions for each package and messing with your path, basher will create a central location for all packages and manage their binaries for you.