Coinbase card is a visa debit card which is connected to your coinbase account. It allows you to use your cryptocurrency in your account.I didn't need to keep my balance in GBP or EUR for it to work. For now I can purchase in stores (some stores) and online using bitcoin (BTC) Litecoin (LTC) or Bitcoin cash (BCH) which would have been s stored in my account.
Coinbase announced their crypto credit card__coinbase card on 11 April 2019. But the transaction fees are too high and the app security is too poor because it doesn't ask for a password when opening the app