As stated on HTDC's DCIL section:

"bitFlyer USA - bitFlyer is Japan's largest digital currency exchange with $1b+ in daily trading volume, and the only exchange licensed in the US, Europe, and Japan. Founded in 2014, it provides retail and institutional investors secure custodial wallet services for both legal tender and digital currency to facilitate trading activity. In 2017, bitFlyer expanded to the US and is now available in 48 states and territories. bitFlyer USA is a wholly owned subsidiary of bitFlyer Holdings, Inc. (based in Tokyo, Japan) and is headquartered in San Francisco, California."

Conclusion: Bitflyer in particular exists as a platform more suited to daytraders. Trading top assets like Bitcoin, Ethereum, Ethereum Classic, Bitcoin Cash and Lightcoin only. We don't find whole lot special about this platform.

Sources: DCIL Participating Companies - HTDC 

Secure Cryptocurrency & Bitcoin (BTC) Exchange | bitFlyer USA