@Marc is correct... no way to convert any crypto except BTC, ETH or LTC directly to fiat $... and even that I believe is only available on Coinbase at this point in time. So to convert any but those 3 to fiat, you must first go to an exchange... polo. bittrex, etc and convert to one of those 3, then transfer those proceeds to your corresponding wallet on Coinbase. From there, it is very easy to cash out in fiat $, esp if you already have a bank acct or debit card linked to your account. You simply sell your BTC/LTC/ETH and direct the proceeds to your $ USD wallet, then choose cash out option from there. They say it takes up to 2 days but all of my requests have shown up in my bank acct in 1 day.
This is obviously not optimal since it is a multiple step process, so this really seems like a great opportunity for some companies to fill a gap.