The multi-currency mistake I wanted Tanda to avoid

I’m an expat, so I spend money in several currencies while thinking about my finances in one base currency.

Many expense trackers can convert currencies, but the conversion date changes the meaning of your history. If an app recalculates an old purchase using today’s exchange rate, the value of that purchase changes whenever you reopen the report.

I designed Tanda to convert each expense into the user’s chosen profile currency using the rate from the expense date. Tanda keeps that historical rate with the expense, so an old spending report does not change because the currency market moved.

This looked like a small implementation detail at first. For anyone living across currencies, it determines whether the spending history can be trusted.

Tanda launches tomorrow.