Looks interesting. Always looking at apps in this space, but I've found a good rhythm using 2do [https://www.2doapp.com/]. It allows you to set a "due" date, a "start" date, or a duration for a task. I also use the "snooze" feature a ton because it allows me to repeat a notification in 5 minutes, 1 hour, 1 day, etc if I cannot complete it at the originally set time.

I also use Things as others have mentioned but for more ad hoc tasks and reminders. 2do is great for my daily routine tasks and others that are recurring.