I was never a very good math student and over the years, I simply forgot a lot of math. But sometimes it annoys me to no end, because I work in a mathematically related field (applied statistics) and feel like an illiterate must feel when visiting a book club.
I would really like to improve my math skills (particularly) Algebra, but I have found few good books and I would like to have som websites or, even better, offline math trainers for the computer.
The reason for using a program is simple that I commute two hours per day and using a laptop / tablet in a train is easier than juggling books and a textblock.
Then you just want to pick up a gcse/ A level core maths textbook, and keep going over examples, with things like factorisation, theres not much theory so it really is practice makes perfect.