I had a brain training "app" on an old nokia of mine and it vastly improved my ability to tally up a list of numbers. That's the only real world improvement I observed. However I did get quite good at those tests.
I might be quite backward in my thinking here but... I pay my isp for a subscription to access the internets (every last one of them). The specific contect I choose to receive or block at my end is my own damn business. It's like being banned from walking down the street because I chose not to look at the billboards!