I recall a couple of years ago I set up a few infopath forms with approve / reject buttons in, that would then approve or reject the nintex approval task. (This was with Nintex WF 2010).
I've been looking for something similar for 2013, but can't find any documentation. The original doc I used had a step by step example on how to set it all up. Does anyone know where I can find this for Nintex Workflow 2013?