Just wondering if this exists, because I have a mini keyboard without these controls, or aftertouch.
 
I have several full sized keyboard controllers with bend and mod, but I was thinking what if I was just using the mini with my laptop when traveling for example, any compact way to add these controls?

Ya a quick look on Google and you find a lot of posts same question and no solutions other than  buy a mini with the mod wheel.. but this one below, I'm sure you probably saw it too, seems a portable solution. Use an i pad controller app. 
 

Yup, that is why my mini stays in a drawer.  Might pull it out someday and try using it for keyswitches...