Hello,
We haven't developed exactly similar app, but we have developed an app for a shipping company that can track all its vehicles on the road. It uses features that can be used in the daring app too.
You will have to give us detailed requirements so that we can tell you how exactly we will develop the app.
You don't have to pay in advance. You can pay after 1 or 2 modules are done.
Thanks and Regards,
Bhargav Mehta