I am in the process of choosing a good online task manager for work. Maybe you can recommend some proven option? What task manager do you use yourself at the moment? 

I've tried a bunch of different tools to automate planning and make the right schedule for my business, and the one that has worked best for me is Voiset's AI-based task manager - https://www.voiset.io/task-manager. Not only does it help you make plans, but it does it more correctly and efficiently. My work has improved and optimized significantly with it.