Phone app to find tradesmen and customer?

Would anyone use an phone app, which matches your home emergency need and location, to an suitable tradesman?

The customer uses the app to send in their emergency request, and their location. Any builders in the area that are available would show up on an app and could click accept.

I don't know how that works but I wouldn't deal with anyone unless they have a valid address.

There's Local Heroes? http://www.localheroes.com/