It's actually Iver Johnson.
They started out making bicycles, and moved into guns, and were still in business in one form or another until the 1990s.
Not the top quality pocket revolvers, but they were well thought of, and certain much better than a lot of the "suicide specials" that were made in the last decades of the 19th and first decades of the 20th centuries.
No, they're not worth very much.
And be careful, some of the early guns should ONLY be shot with black powder loads.
That said, I've had several IJs over the years, and even carried one as a back up for a time.