I know that there are various minyan-finding sites like godaven.com They tell you the location and times of the closest shul to where you are located.
Is there an app that can locate Jews who are already on the road? For example, you're driving on a U.S. interstate and you know there is a rest-stop ahead. You'd like to either form a minyan or find someone who is about to form a minyan. Is there an app where people could subscribe to receiving notifications that a minyan is about to form near your location?
If you know of any, please indicate which O.S. it works on.