I have been using Lumosity regularly for a couple years after receiving chemo and radiation. When I first started I could not remember 3 numbers in sequence, people's names, passwords and some words.
When I use it regularly I notice a huge improvement. I'm up to remembering 18 numbers, 80% of my passwords (if I have not used them in a long time than retreaval is still hard) but the results pay off every day for me. If I take an extended leave from practice I notice this in my daily work. This program has been a godsend.