The ap itself is user friendly & well set out. My low rating relates to Coinbase itself. I used to be able to sell crypto & cash out same day, but on my last trade my funds were placed on hold for 7days! Reason for hold kept changing with last reason being a security measure for my own protection. There were no means to reduce this hold time, despite numerous requests to release my money. So coinbase got to earn interest off my funds while I had to wait 7 days to get access to it!! So beware!