Yes, Flowrev supports multi-currency.  Specific subscription plans include this capability.

When an invoice or bill is created in a different currency from the organisation's base currency, QuickBooks registers an exchange rate into the base currency on the invoice/bill.

Flowrev uses this "invoice rate" to create schedules, which are then syncd back to QuickBooks when the user sync's schedules.

Any currency gain/loss that occurs due to the actual rate received upon payment will be shown within QuickBooks as realized gain/loss, and prior to payments received as unrealized gains/losses.

In Flowrev, the invoice exchange rate and the payment rate for each invoice is shown on the invoice details page - note: the invoice rate is used for schedule computations and to display amounts in summary reports on the Home or Revenue page, etc.  The same applies for bills.

For example, the invoice shown below was raised in GBP, whereas the org's base currency is USD.  Flowrev will generate schedules for these invoice lines using the "Inv. Rate"