Ask HN: Is there a wifi setup tool for the Raspberry PI similar to Chromecast?

The Chromecast wifi setup is dead simple, and it allows for anyone to setup (and re-setup) a secured wifi connection without having to do anything beyond their comfort zone (like connecting a keyboard and doing cli stuff). The genius of it is that the general public is now capable of setting up the wifi on an embedded device, and it just works.

I am looking for a similar type of solution for the RPi. It would be amazing to be able to put the access code on a cheap 7-segment display, for example, to make a wall wart type of device for family members, but without the need to personally set it up over and over again in the future.

Does this type of solution already exist (and is my Google-fu failing me)?