What attracted me to FXOpen was it looks like you can move relatively easily between USD, BTC, and a handful of altcoins, and it's laid out in a way that's similar to traditional Forex. I was going to go for it, until I saw that I can't because I'm a US resident.
So basically I'm wondering if there is a platform that is like Forex in speed, cross-currency trading, and not too crazy a learning curve, like FXOpen, but can be used in the US.
1Broker and recently created WhaleClub.co are great for trading forex pairs along with some other equities and commodities.