Normal $49 US, down to $1 US.

What it is, from Wikipedia:

Shodan is a search engine that lets the user find specific types of computers (webcams, routers, servers, etc.) connected to the internet using a variety of filters. Some have also described it as a search engine of service banners, which are metadata that the server sends back to the client.[1] This can be information about the server software, what options the service supports, a welcome message or anything else that the client can find out before interacting with the server.