Forever is a tool with two functions. One function saves your current directory to a tmp file. The other cds you into the directory stored in the tmp file.
This is nice when you want you've got multiple tmux panes, and want to quickly get one pane to the same dir as another.
Example:
cd foo/bar/koo/kar
fdir
# ctrl+b n (next tmux window)
gdir
cat fdir.sh >> ~/.bashrc
cp fdir.sh $ZSH_CUSTOM/fdir.zsh