Please comment with additional resources or apps and they will be added to the master list. [Note: I could use help with suggested apps for Apple/Android! Please supply a link if possible, as well as if it's free or costs money.] Please comment or let me know if there are any dead links.
Please do not link to pirated material or any sites that function to provide copyrighted material for free. No "free" Goljan/Pathoma/Kaplan/etc. Posting these links is a violation of SDN TOS.