Do you need to register a transaction made with foreign currency? On Mobills you can do it with the inversion of currency feature.
When creating an expense or income, you can touch the icon next to the value of your expense:
After that, you can pick the nationality of your currency, check the variation with the currency you are using and fill all necessary fields. After that, when you save the transaction, Mobills will convert the value of the foreign currency to the currency you are using on your day to day usage of the app.