‘Todoist’ is an application which is available on all the platforms. It is fast, clean and easy to use, which is what puts it in best category. It has features like custom labels and filters, location-based reminders, and templates for recurring projects.
You can also collaborate with your co-workers with this application. Todoist is that one app which can be used for both complex and simple tasks. The basic plan is free and gives you access to all major application platforms.