"App to let criminals know where the easy targets are". Even turning it up once, while you are at home, is enough to put a mark on your back. And people generally don't exchange currencies that often, so there's no need for such an app. Existing solutions like forums, chat groups, social networks, etc. work just fine.
Yeah, it's too risky. Although at first sounds like a good idea security of people who would use it.is a big issue. They would expose themselves to a big risk, although I'm sure some would have take it. Even chats and forums are a risk because of scamers and with such app people would expose themselves even to physical risk, not worth it.
