It shut down, but you can easily launch a version of it when you download the platform:
https://github.com/dhcrusoe/Boolify
boolify.org was unfortunately shut down, but we are now hosting a version of it on KidzSearch.com See http://www.KidzSearch.com/boolify
Thanks so much for making the code available. We are now hosting it on https://www.kidzsearch.com/boolify and will make it open to our users. All your hard work will live on to help kids out. Will do our best to keep improving it.