Ask HN: GTD tool for Windows that works with iOS?

Hey all - I currently manage 20+ people and depend on OmniFocus (on Mac and iOS) to keep track of everything to talk to them about in our 1:1s. I love the ability to set a due date, defer being reminded of the item until that date, and slice and dice by assigning actions to contexts. I also love the quick entry hotkey. Does anyone know an equivalent app for Windows that would also work with an iOS phone? I'd like to get rid of my MBP but keep my iPhone. Thanks!