I like using Google Tasks in combination with Google Calendar. I like to use this app instead of actual Google tasks, because it allows me to collapse nested tasks and to give a priority to tasks. Also, I can see all tasks due today and in the coming week.
The only thing that needs improvement is that when you sort tasks by priority, nested tasks get split up, which makes it a bit chaotic because you don’t know which main task a nested task belongs to any more.
I do recommend this app for anyone who uses Google Tasks.