Ok, first off, this has been and I assume still, a great app. It is tied to trains’ reporting so, if they stopped reporting their location, there is nothing the developer can do. Blame the MBTA, not the developer or the app.
However it stopped working two days ago without explanation or any other prior warning. Either an update went wrong or the developer just quit and relocated to another dimension. Whatever the cause, it harmed thousands of people relying the info. Bad part is, since it is a great app, many people started to trust/rely on that completely so any error that lasts this long is definitely causing problems more than one can anticipate.