I wasn't sure if I needed this book to work with Spelling Power - but I'm VERY happy that I did. I love that all of the spelling words are in one place. I can track my daughter's words and she has been using the multiple-step process page and is finding it very handy. I love that we can track where we're at on the back cover too. Somehow doing this on looseleaf paper doesn't feel as organized and official. ;D Worth buying for sure! My only 'dislike' is that the paper is fairly 'dark' - newsprint rather than white paper. I suppose if white paper would be more costly. This is fine.
This product is not needed to make the Spelling Power course work, but for the extremely affordable price it makes life much easier. No loose papers floating around and it keeps all the children's information in one place. Easy for yearly reviews or record keeping.