[quotient]

Great stuff. Beautiful feeling to the site, though the 'Train' section could do with an explanation as to what you're meant to do on the exercises ('tactics'). I'm tempted to suggest integrating this with en.lichess.org, a similarly awesome chess-resource.

[Matetricks]

An onboarding process for "Train" is in the works - right now for the beginner player, this section is rather overwhelming and he or she probably would have no idea what to do. The objective is to find the best move in any given position but that information isn't very obvious.