zsh-expander is a zle widget ("zsh plugin") that allows you to write custom expansions and select them with fzf. For example:
$ git revise .c<TAB>
Will let you select a git commit to revise.
It depends on fzf and perl.
This is different from typical zsh completion because it's entirely predictable and works for any command: completions are only based on the trigger word that you type, not the completion script for the command you happen to be running. It is also much faster than builtin shell completion.
Currently the triggers are hardcoded:
.bgit branches.cgit commits.ddirty git files.fany file/directory, recursively
But a future version will make them configurable.
This isn't really... released yet. This is just me trying to clean up my .zshrc.