RUON is going to be on the BEOS blockchian, which is a fork of EOS. It is a middlechain between Bitshares and EOS. RUON is another appealing application focusing, it looks like, on mobile. The project is concentrating its efforts on providing money to the 3rd world and ending global poverty.
There are going to be many of them appear on the scene over the next couple years. As we see with Steem, it is highly likely there are a number of ones one each blockchain.
This is good IMO. I think the problem is a lot of people are looking for one singular solution for things, but this a rather old way of thinking. There can be a variety of social media services that offer similar features though cater to a different audience or market; we don't need one type of facebook, reddit, instagram, etc for all.
Decentralization is the main social theme that is taking place so the more the better really. Of course there maybe only one that rises to the top but why does that necessarily matter? EOS can be the Microsoft of crypto, Steem the Linux, and ethereum the Apple.