Ok, it looks like a good idea, but I'm not convinced on how much fabric it actually saves. You are still cutting away part of your square and throwing it away. The squares you make and cut in half are cut larger than the squares you cut using the square sewn onto a square and trim away method. You trim off the excess and throw it away and have one little triangle from the base fabric left that may or may not be usable. I also find it hard to be accurate when cutting my squares in half from corner to corner. I waste fabric when my ruler is not positioned just right.
Honestly, I'd rather use the two-whole squares method, because I've found that to be much more accurate for me and I carefully trim off the triangle corners (which are now exactly the same size). If they are large enough to do anything with, I sew them together to make little mug rugs, pot holders, or doll quilts with them. Then I'm not throwing anything away. If they are not large enough to do anything with and I need to throw then away, I've not wasted much.
That's just my opinion. I'm not trying to throw cold water on someone's invention.