It _was_ a product for the iPhone 4 / 4S back in the days, and I testwise adapted it to my current iP13mini.
It was made by Tchibo (TCM) with article number 290269.
Today, there are plenty of those snap-on and phone-case based zoom lenses (and others, as pole filters, fish-eyes and so on). I just did not find any really convincing solutions so far, but keep searching. It´s also difficult as phone generations pass by every other year, making new adapters needed each time...