At home I have a local network with five computers, two phones. I'd like to be alerted or scan my local network to see if a person is using my connection for internet. Why, for a month, every day between 20h and 22h my connection is tested and I find myself with my ping up to 10000 and HD TV freeze. The normal operation of the network with a ping of 40 so the cyclical difference is not due to my installation. I have used paid apps with a 30-day trial that gives warnings, but it is a free app would be better, I do not ask a professional soft but just a block hacking WiFi network. The problem is that the ISP provides a code to connect to the neighbor waiting for the installation of their line, so I guess the friend of a friend happens that password. Oh yes, I disconnected the freewifi connection on my router.
Advanced Port Scanner is a fee, so if you know his little brother free. The app detects and blocks it all.