Evercoin is my favorite on iOS. You can hold and trade a pretty decent set of cryptocurrencies and the fees are cheap. They have a great support team that has helped me get back a transaction that I screwed up when I got started with them. They are also open to feedback and enhancement requests. I use that to do allot of trading as well as Robinhood. I just want RH to open up crypto deposit and withdrawals. But the fact that I can trade stocks and cryptos in the same place far exceeds the need for me to have that ability.