Use case:
You have 2-3 files displayed in your MacVim window(s). You press ctrl+Q and MacVim closes. When you restart MacVim it opens displaying the same files you had w
Install this plugin: https://github.com/xolox/vim-session
And add this following two lines to your .vimrc :
.vimrc
let g:session_autosave = 'yes' let g:session_autoload = 'yes'
Now if you close your MacVim/GVim it saves and loads the session automatically.