All these apps are all distributed in some way, because they use a blockchain, but not federated. I think it's useful to have this list to point to, in case people think we just don't know about these apps, and because the non-scammy, free code ones might be worth approaching about implementing AP or Zot to bridge to the fediverse.
Because all these blockchain apps are in competition with each other, unlike the fediverse apps who cooperate on common protocols, it's hard to see how any of them will gain the network effect to compete with the legacy datafarms. Although some, like Resonate and Musicoin, are platform cooperatives, it seems like at least some of the others are just datafarm larvae like Everipedia, aiming to enslave enough users to get Vulture Capitalist funding, and exit by acquisition or IPO - Strypey
Afari (pre-alpha) - a mobile-based social network built on the BlockStack blockchain. Not yet in beta as of 2018/12/20.
Akasha (beta) - a web-based social network app that uses the Ethereum blockchain.
Datong - at this point just vapourware with a Patreon. Can't rule out it being a scam. I presume if it is a real project they will use a blockchain as the homepage says "We will introduce an unique digital coin that you can exchange for services on the network itself."