*about* lichess, that it's free
*in* lichess, probably the custom backgrounds :D
The UI. I play mostly in browser, but most sites are clunky, slow, you know which ones, those who run (ran?) on flash, or a java app or similar. ease of access, pretty colors, lots of tracking of your development, tools, with an engine and three of openings, resources. Even a forum just 1 click away.
And no ads nor trying to sell me something after a game. Im playing chess, not some random candy crush clone game on my phone.
play, chat and lead teams!