Currently all the tasks marked completed show with a gray background. Is there a setting to hide completed tasks?
These tasks should be removed after you resync the app, but please note that sub-tasks may be still displayed (just as they are on the web-app) unless you complete them n the web while holding the Shift key.
Unfortunately, such option is not available on the iPhone app right now, but we're already working on improving the display of tasks and sub-tasks in the next updates.
Thank you and all the best for the holidays.