unfortunately, it's not possible to manually reorder/sort tasks on the "today" view, but thank you for your feedback, we appreciate it and will consider adding such feature in future development.
Feel free to vote for these feature requests in our Votebox:
Currently, the "today" view displays tasks sorted primarily by due time/date, then priority so for now, as a workaround you could stop using due times in some tasks which would automatically sort all today's tasks by priority.
Sorry for the inconvenience.
It would also be nice if we could sort tasks by their categories....