The froe is how wood was split into shakes, shingles, and chair stock for centuries: drive the blade into the end grain with a club, then lever the handle and let the wood split along its own fibers. Wood split this way is stronger than sawn stock because the grain runs unbroken end to end.
Gransfors Bruk hand-forges theirs in Sweden with the same smith-made quality as their axes. For traditional shakes and all fine riving work, this is the genuine article.