I suppose you could use it if you want to but it is just as easy to write it down in a notebook to keep track of it or you can keep a log in your computer. It doesn't have to be anything fancy.
i used some program before. it was ok. it tracked your water changes water tests what fish you had how much you spent on it. i just switched to a excel spreed sheet and i use quicken to track my spending. i think it is a very good thing to track your tank. the more data you have you might be able to pick up patters.