Indian Railways is used by over 25 million Indians every year and is the best possible method of conveyance because of its sheer size and reach. I had already given a timetable App for all phones here for Mumbaikars which is very popular even now.
The Indian Railways introduced a SMS based ticketing service last month wherein you have can avail the services even through most basic phones on 139 or 5676714. Once you have received the tickets on your SMS you can use it along with your original photo id to embark the train.
But getting the tickets itself is a big problem where every ticket gets sold out in 7 seconds or so. I have given out a tutorial for easing the process of booking tickets from the IRCTC website here.
Today or rather yesterday Cleartrip has updated its Android App to include the ticket booking of Railways in the App through IRCTC. With the latest App, you can search for trains and book tickets on the go, anywhere anytime. It also give PNR status of your tickets if they have been wait listed.
The Cleartrip App can be used as you would use the IRCTC's website. It can be used to find trains between stations, availability of seats, train fares, PNR Status all in one.
This is a must have App for every Indian, because every now an then we have to travel by the Indian Railways. You can download the App here from Google Play.
Cleartrip also offers air tickets through the same App. They have not updated the iOS App yet to add the Railways feature, if they do I will keep you updated.