App mostly does it's job, though there is a lot of latency which can be an issue during higher activity periods. You lose about 2.2% when trading between coins, hidden in the conversation rate rather than explicitly stated as a fee. When I attempted my second buy in, Coinbase blocked it, claiming it was suspicious. They won't tell me why (for security reasons), and they can't resolve the issue immediately. I was told to reach out again in 6 days if I haven't heard an update.