From the home screen, tap the cog icon in the bottom right corner to open the settings page.
Then tap the ‘Native currency’ button.
This will bring up a list of currencies from which you can select. The below example demonstrates the British Pound as the default currency.
When you go to make a payment, tap the 'quick tap' button for the amount you want to send. This will automatically calculate the amount of bitcoin for you. For the below example, the £10 button is selected👇:
As shown below, tapping the £10 option will convert and select the exact amount of bitcoin to send.
You are now able to swipe right and send the exact amount of bitcoin that is equivalent to the amount in British pounds you selected. In this case £10.
Alternatively, if your native currency is set to fiat, you can enter the fiat amount first e.g £22.50 and then change the account by tapping the dropdown and changing to the bitcoin account. This will convert £22.50 worth of bitcoin to send.