We use FreshDesk as a dispatch solution for field technicians. It works great but it's not exactly designed for that. Why not take it all the way? The only thing you need are en-rout, on-site, complete buttons (with timers) and time stamps.
Another useful tool would be to have the system push one job at a time to a tech, rather than show them the whole pool. We could manually split them up into regions of the city as different groups.

