I have been using the Lumosity website to help keep my brain going since Sep. It has really helped. I use the free games. There are three that you can do each day. If you want to pay you can unlock other games and features. It tracks your progress and you can actually see over a period of time where you are improving. It's free and it helps so that works for me.
I so believe in training for Cognitive thinking. I think they make it fun. It's like doing the Wii but just with the brain.