Still the best for me - and I've used a LOT – TickTick:To-Do List & Calendar Review

This app does a great job of balancing the right amount of detail, along with the right amount of simplicity. It runs on absolutely anything, which is perfect when you work in a MS Windows world, enjoy Mac at at home, iOS or Android and the go, or the web when none of the others are available. Attachments, adding tasks by email, good tag management, reminders, acceptable sub-task usage, KanBan, Pomodoro, enough themes to get the GUI feel that you want, and a premium version that's inexpensive enough to sell the whole thing. As a a person who has a serious app use addiction, managing my tasks is one area where I never look to find something different any longer. I think this is one of the most underrated apps in the App Store.
Review by OinkyJates on TickTick:To-Do List & Calendar.