From what I can gather it's some kind of dodgy Shareware thing. Although I can only guess since they really have made little effort to make it any more clear.

Neither the "purchase" site [1] nor anything inside the app itself [2] clearly explains the terms of the free download, or why one should even consider purchasing a licence.

I understand this is a fresh product and everything but it's expected one makes an effort to make these terms far clearer before asking for people's money.

Is this a simply a case of neglect or an example of a dark pattern [3] in the wild?

[1] http://wingmanapp.com/purchase

[2] http://i.imgur.com/aD5g8.png

[3] http://wiki.darkpatterns.org

What makes shareware dodgy now?

Nothing. You've misinterpreted. Or I've miscommunicated. Perhaps both.

Read what I wrote again without presuming I'm universally referring to all Shareware as being dodgy; just this particular instance.