Keeping all the characters straight in George RR Martin's A Song of Ice and Fire books (and the Game of Thrones TV series) can be all but impossible. There are many online resources and wikis, but everyone I know who consults those always comes back with the same complaint: they got spoiled. You go to look up Character A, because you forget what Character A was doing 500 pages ago, and you find out Character A is killed in the next book. It's a huge bummer.
Random House, the company that publishes the novels, has the solution. They've created a smartphone app (a fucking HUGE one, by the way. Make space on your phone) that is a guide to the characters and locations of the novels. But here's the rub: the guides are presented in installments, so you only buy up to the installment that covers the books you've read. That means you can look up Character A with no worries about getting spoiled to hell. And since the app lives on your phone, you don't have to worry about being online to consult it.
I don't know how long until we get the next ASOIAF book, but in the meantime this can scratch your Westeros itch... at least until the show comes back in March.
You can find the app under the unwieldy title George RR Martin's A World Of Ice And Fire.