If you are in a FD, on a HAZMAT team, in EHS at a facility with HHC’s that could have an offsite impact this is the BEST $5.99 you will ever spend. This app is GENIUS and just blows away the Green Tables in the 2008 DOT ERG. This app has the DOT ERG chemicals and you look them up by UN # or name and you choose Large/Small spill, Day/night, etc. and the thing gives you a plume laid over google maps, both street view and satellite views. It even goes and gets weather data from your immediate location and shows you the exact plume travel direction and distance. I feel like Christmas was two months late! You can download it from the Apps store or you can view it from the company’s website Here.