flx is a very smart sublime-text like fuzzy/flex matching library. I already use it for my hippie-expand, but it would be really cool if auto-complete could use flx to sort matches, it would dramatically reduce the keystrokes required.

(kcdg<tab> eism<tab> "jj" ens<tab>)

Becomes

(key-chord-define-global evil-insert-state-map "jj" evil-normal-state)

Vim has YouCompleteMe, but it uses a form of flex matching which seems simpler than flx.