Many people would argue that it's ethical to break an unjust law, and in fact that's the only way any real societal progress has been made. From drug decriminalization (including alcohol), to minority rights, to the very founding of many countries. Still other people seem to hold a conflicting stance where they rightfully idolize historic lawbreakers like George Washington or Rosa Parks, but any breaking of current laws is "always a bad thing".

That said, in many countries it is only illegal for residents of that country to facilitate foreign money services for others, it's not strictly illegal for them to take advantage of money services that do exist. In those cases, a borderless app doesn't actually break the law.

Basically, I can't agree with you that it's "not a good thing" that Argentinians are able to hold 10 dollar balances on their phone so that they can afford groceries next month. I think that's a good thing. People can afford groceries who weren't able to before.

By the way, I'm going to adjust that bar one more time. Good applications are ones where the added value "cannot be attained with less effort by other means", not where the added value "cannot be attained by other means".