Leverj is this custom Plasma side-chain non-custodial DEX (decentralized exchange that doesn't store your funds in some pooled address, running an SQL database on top and then wondering how bad things happen...) that I had previously written about and covered briefly (since it is the first implementation of an accounts-based Plasma design, which I thought a pretty significant step).The implementation is really something of a hybrid exchange, since it maintains a centralized order book and order matching engine in order to ensure industrial-grade speed and efficiency (running on a Proof-of-Authority chain, meant to upgrade to its own PoS in the future, one propelled by a pair of platform tokens, LEV and FEE - the economic levers of the platform, so to speak) - settlements and exchange take place in a decentralized fashion (similar to also Waves).
Anyway, Leverj just went live (at live.leverj.io). Not much of a trader myself, but this does sound cool & potentially of interest. Registration and authentication takes place via a zero-knowledge scheme (no user/pass) and there's APIs and SDK libraries (Python and Node.js) provided (which I haven't yet taken the time to look at). On the same note, XDAI is another side-chain that came to my attention these days, that translates Dai (the MakerDAO managed stablecoin) to the Plasma dApp (thus minimizing gas fees and such). Really looking forward to see how things develop on that front. Some easy money made in the process of actually learning something are always welcomed.