The best alternatives to Friendsome are FasterThinking, Supermind, and Shapes of Cities. If these 3 options don't work for you, we've listed a few more alternatives below.
Lots to remember at work? Need to quickly onboard to a project? Keep having to google the same thing? Supermind is the easiest way to improve memory in all you do. It uses the "spaced-repetition" memory technique in an approachable, lightweight way.