I was thinking the exact same thing while reading this. Wunderkinder is missing and the majority of these companies are copy-cat businesses. Granted, Wunderlist is a to do app which there isn't a shortage of, but they've managed to keep their product free while maintaining cloud sync, great UI, and relevance among its productivity community. Meanwhile they opted to include a general "rebate networks" and deal network companies. This is my long-winded way of saying this list is mediocre and Wunderkinder deserves to be on a list like this.