Can I just add to that that this would also be a great feature for the “analysis” (spending) menu in the app? Like, I’ve spent in euro and yen this month but I always charge in euros. So I’d like to be able to see a total spent in euro.
In my mind this would work like this: whenever a payment had been made in a currency other than the base currency (euro for me), it also saves the amount of base currency you spent on that transaction so you can get a total in your base currency of the month.
I.e.: I have €300 in my account. First I use it in Belgium and pay €10, then I arrive in Japan but haven’t converted anything to my JPY account yet, make a payment for ¥12700 (which at this day was €100), then after a few days I transfer €100 to my JPY account (the rate is now €1 = ¥130), so I have €90 left and ¥13000. Say I’ve spent ¥10000 of that by now (=€76.923 with the exchange rate I got at that time) and none of the euro account anymore.
Then I’ve in my spending menu: €10 and ¥11270; and in my availability/wallet menu: €90 and ¥3000.
Now the idea: display a real spending master total in my base currency of €186.923 (€10+¥11270 with the exchange rates at the time of respective conversion €100 and €76.923) and a real available master total in my base currency of €113.077 (€90 + ¥3000 with the exchange rate at the time of conversion of that part giving €23.077).
This turned out to be more complicated to explain than I envisioned
I hope the numbers are right and I was able to convey my idea