This is also one of my favourites and I often wonder how I survived without it, so far. The key function of this app is that it gives you the Mumbai Train and Bus Time Tables at the tap of a key ! The train time tables are for Western / Central and Harbour lines. So say, if you are at Andheri and are proceeding towards Churchgate, just fire up this app and it will show you all the trains going from Andheri to Churchgate, from the current time onwards. It has also been updated for the Dahanu Services.
For the bus services, you can just enter From and To locations and you can find the bus routes which take you there. Besides, if you enter a bus route no., it will show you the entire route of the bus.
As a bonus, you have the listings for Cinemas / Drama, Picnic Spots around Mumbai, Railway Megablock information, Indian Railways PNR status check, etc.