Yeovil is, by far, the worst place I've been recently for this. First (ah! yes that is the main operator too), you can generally forget about real time displays there anyway. I was there in September, a couple of weeks after the local network had been changed - and new timetables had been put up at the bus station (and elsewhere) that were entirely incorrect (suggesting the two main town services only ran every 70 minutes, which had never been the case, instead of every 35 minutes). The whole issue of how the routes are numbered (and change number at the bus station, having served the main stops in the town centre first) is another complicating factor. And of course there are no maps on display anywhere. And across the town in general, lots of outdated timetables and no apparent effort to maintain them.
In my experience of the Stagecoach App, the Cheltenham & Gloucester part of Stagecoach West manage to indicate services as cancelled in the app, but the Thames Transit part never does.
In my experience of the Stagecoach App, the Cheltenham & Gloucester part of Stagecoach West manage to indicate services as cancelled in the app, but the Thames Transit part never does.