Need to add one more stage after task is completed like "Verified" or "Approved".
Need to add one more stage after task is completed like "Verified" or "Approved". So manager can follow just finished tasks and approve them.
Personally I'd live to see custom statuses or allow a status to be tied to one or more Buckets (so that moving the task into that bucket would change the status automatically). I realize that starts to get into automated workflows (which also could be a great future integration).
If Planner allowed for dependent tasks (that can't be completed until another task is completed) the final task you want would just be another task dependent on one or more preceding tasks being completed. Assign it to the manager and you're done.