I disagree its not useless. Especially if your someone relatively new to planted tanks or co2 Injected. With the every few day reminders and the links to further information on things like trimming etc it helps keep on top of things and prevent any newbie errors too.
I ran it for the full 90 days just to try it and thought it was very informative.... and its free
I have it on my phone and although I dont use it to the letter ( im doing 80% water changes daily for 3 weeks now) I think its pretty good, as Alastair said the links to info and reminders are a great idea, with my next tank I might follow it and see the outcome but for beginners I think its great and as far as im aware there nothing else like it available
Good guidance if you are a beginner in planted tanks... at least it helps you to understand some logical steps. But I supose it is useless if you have some experience. Soon (with more or less mistakes and/or quite a lot of hours reading threads in this forum) you begin to "read" your tank and you don't use it anymore.