Transactions in different currencies
Every account has its own currency, and a transaction always happens in the currency of its account. Balances are shown as they are: roubles in roubles, dollars in dollars. The app does not roll them into one “total” on its own — that would be an invented number, because the rate changes daily while your money really does sit in different currencies.
A transfer between accounts in different currencies is the one place with two amounts: how much left one account and how much arrived on the other.
You almost always should: an exchange office, a bank or a friend will not give you the textbook rate. Enter what actually happened — the app remembers those two amounts, not a rate. The rate is never stored and never carried into the next transfer.
Rates themselves are only used for that suggestion and for converting inside Analysis. Refresh them in Settings with the “Refresh” button — the line next to it says when they were last loaded. The request goes to an external rates service, so refreshing needs a connection.