Singh said in a phone interview he was planning to include bus timetables, a planner tool and information on service interruptions in the next version of the application, which is being bought by iPhone users at a rate of about 20 copies a day. But Singh recently received a threatening email from RailCorp advising him that if he did not remove the application he would be sued for copyright infringement, as RailCorp owns all of its timetable information.

Singh said he did not have the resources to take on the Government in court and his legal advice suggested he would probably lose the case. So he will most likely withdraw the application from the App Store. "I've asked them to send me a formal written cease and desist notice before I take it further," he said. "The argument they've said is we are in the planning stages of getting our own application up there, but going by the Government's past performances I don't think we'll see it any time soon."

RailCorp would not comment on whether or not it was developing its own iPhone application. "RailCorp's primary concern is that our customers receive accurate, up-to-date timetable information," a spokeswoman said in a statement.

"This includes details of service interruptions, special event services, trackwork and other changes. Third-party RailCorp timetable applications may contain inaccuracies and have the potential to mislead our customers." Since Singh's application is based on the fixed timetables provided on the RailCorp website, it does not account for service delays. Singh said he was not looking to profit from the application and sold it only to cover his costs. He said he would give the code to RailCorp for free if it wanted to build its own version.

"It's in the public interest for them to have this out there and the argument they gave me was they plan to release their own one but they've had two years to do it and they're a corporation; they've got lots of people to do it, and I did it over a few weeks in the December break." The Victorian and Western Australian governments have been far less draconian when it comes to iPhone developers. The Metro Melbourne, Metro Perth and iTT Perth applications have provided public transport timetable information for some time.

Google Maps offers transport timetables for Adelaide and Perth, but Google has not yet been able to secure the rights to provide the feature for other cities.