We've all had this happen: your phone rings and the caller ID shows only a number because the contact isn't in your address book. You've no idea who it is, so you reluctantly answer. Turns out it's either someone you don't want to talk to, a wrong number, a bill collector, or some other person you'd have rather avoided.
Before today, an app called Mr. Number could've made that scenario play out a little bit differently. The app had a feature called crowd sourced caller ID, which - get this - shared your entire address book with other Mr. Number users.