If you can't see a task that you just created, it is probably hidden by a filter. Do you have a category or location filter active? Those are enabled with the and buttons. If not, the task is probably not yet available to be worked on. If the task's start date has not yet occurred, it will not appear in the task list, unless the "Show Unavailable" filter is active. You can enable that filter by tapping on the button. Also, completed tasks aren't normally displayed in the task list. You can view them by tapping on the button.