Works about 50% of the time

I use this for the red line and blue line, so I cannot speak to how it works with the orange/green. But with the blue/red it does miss about half the time; it will just give wildly inaccurate predictions and when I get to the actual train stop its pretty disappointing. So I would say use this app when you are not in a rush or actually dependent on it-make sure not to rely on it.

Tunachrissy about ProximiT: MBTA Boston Transit