When you asked, printman2000, about apps for rail travel I thought of BART[bay Area Regional Transit for anyone who is not familiar with the Bay area in Northern California] (as I'm located in Sacrmaneto, CA). They have an app for that (surprise!) called iBart. I went online and founda whole list from BART's website of rail and municiple travel apps:
Free Apps
NAME: BART Departures
PLATFORM: Facebook
DEVELOPER: Platform Associates
WHAT IT DOES: look up real time departures, message friends when taking a BART trip
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NAME: BART Planner
PLATFORM: Mac OSX
DEVELOPER: Definition LLC
WHAT IT DOES: Scheduled trip plans
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NAME: BART Rider
PLATFORM: Android
DEVELOPER: Sinan Akay
WHAT IT DOES: Real-time departure information and alerts
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NAME: BART Live Arrivals
PLATFORM: iPhone, iPod Touch
DEVELOPER: taapuna.com
WHAT IT DOES: Real-time departure information (1 station only), system map
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NAME: BayTripper
PLATFORM: iPhone, iPod Touch
DEVELOPER: Jerald Jariyasunant and Eric Mai
WHAT IT DOES: Real-time transit trip planner that includes BART and other agencies
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NAME: Estately
PLATFORM: Web
DEVELOPER: Estately, Inc.
WHAT IT DOES: Search real estate listings by proximity to a BART station
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NAME: Google Earth / Google Earth for iPhone
PLATFORM: Various
DEVELOPER: Google
WHAT IT DOES: Station, route and schedule information in the transit sublayer
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NAME: Google Maps / Google Maps for Your Phone
PLATFORM: Various
DEVELOPER: Google
WHAT IT DOES: Trip planner, station information, cost of BART vs. driving
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NAME: iBART
PLATFORM: iPhone, iPod Touch
DEVELOPER: PanDav
WHAT IT DOES: Trip planner, station information, scheduled arrivals, delay advisories, system map
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NAME: NextBus Mobile
PLATFORM: Mobile web
DEVELOPER: NextBus Information Systems
WHAT IT DOES: Real-time departure information (currently in Free Trial beta mode)
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NAME: TrainText
PLATFORM: Twitter
DEVELOPER: Mason Blake
WHAT IT DOES: Two-way, SMS-style real time information via Twitter
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NAME: TransiCast
PLATFORM: Android
DEVELOPER: Joachim Pfeiffer
WHAT IT DOES: Real-time departures, station information for BART and other agencies
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NAME: Transitly
PLATFORM: Web app for iPhone, iTouch, Android
DEVELOPER: Liquid Mongoose
WHAT IT DOES: Scheduled departure times, remembers preferred trips
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NAME: The BART Widget
PLATFORM: Mac OS X Dashboard
DEVELOPER: Bret Victor
WHAT IT DOES: Trip Planner, system map
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NAME: The Next Train
PLATFORM: Mobile web
DEVELOPER: Jehiah Czebotar
WHAT IT DOES: Trip Planner
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Not Free Apps
NAME: BARTdroid
PLATFORM: Android
NAME: BART Live Arrivals Pro
PLATFORM: iPhone, iPod Touch
NAME: Bartomatic
PLATFORM: iPhone, iPod Touch
NAME: iBART Live
PLATFORM: iPhone, iPod Touch
NAME: iTransitBuddy
Platform: iPhone, iPod Touch
NAME: MuniApp
Platform: iPhone, iPod Touch
NAME: NextBART
Platform: iPhone, iPod Touch
NAME: NextTrain BART - AR
Platform: iPhone, iPod Touch
NAME: pBART
Platform: Palm Pre, Palm Pixi
NAME: Routesy
Platform: iPhone, iPod Touch
NAME: SF Subway Maps
PLATFORM: iPhone, iPod Touch
NAME: The Next Train
PLATFORM: iPhone, iPod Touch
NAME: TransitGuru BART
PLATFORM: Android, iPhone, iPod Touch
NAME: RailBandit
PLATFORM: Blackberry, Nokia, Samsung, SE J2ME
NAME: Tube
PLATFORM: Blackberry, iPhone, iPod Touch
NAME: UniBus
PLATFORM: iPhone, iPod Touch