Ive had the same one for almost ten years. Sometimes called the “two-bit snapper” it’s a very simple and clever spring-based hammer that you use instead of the nail set-hammer combo normally used to pound in finishing nails. It’s excellent when you need to put up molding in tight spots and corners. Its compact size means that it can always live on your tool belt. You just pull back one end and the spring does the hammering for you.
It seems to be a lot more accurate than a center punch-hammer combo, since one hand holds the tool and nail together, while the other pulls back to snap the spring; you get fewer errant holes around the nail you’re trying to punch in. It’s one of those tools that is so simple, I wonder why more people don’t have one. I’ve only used it for finishing nails, but Spring Tools makes it in other variations, as well. This tool is just so elegant: simple, functional and as utilitarian as a bicycle.