I'm not sure I would consider them "smart", but they are definitely exhibit an awareness of their surroundings that is not as obvious in other arachnids or arthropods. It's fun to watch them explore their terrain, stalk and catch prey much larger than they are, and of course jump relatively large distances like pros.
Here in AZ we get a fairly big jumping spider with a red on the top abdomen, we call 'em red butt spiders. No one harms the red butt spiders! If one is down at person level I like to gently interact with it. If you slowly move a finger near it, it will rotate and examine, and then scoot an inch away. Not too fearful. Usually a single one wins out, and will live with us until fall. A familiar housemate. We also get fairly big tarantulas, maybe 4" across the span. (Outside) They don't strike me as intelligent, not like jumping spiders. I always stop and scoot them off the road when I'm biking. I have seen a tarantula hawk hauling one much bigger than itself in my yard, off to its doom.
Like you, on reading the title of the article, I thought, I bet it's about jumping spiders!
Really, all animals are relatively smart (ignoring individual differences in a species), in that they have specific skills and abilities that allow them to be most effective for their biological makeup, and purpose in their respective ecosystems.
We humans are no different in that regard ~ we are relatively smart, in that our biological makeups grant us leanings towards skills and abilities that other animals don't have.