Good news for Mumbaikars! Finally, you can now track your local train in realtime. The M-Indicator app, that is popular with 8 million commuters, has now gone live, by community-sourcing. It manages to track down realtime train timings by sharing location updates from commuters.

If you are on the platform, it sends you an alert on the arrival time of the next train and if you are on board the train, it asks you if you are 'in this train', after which the app informs you to get your location information. The algorithms then use this to calculate the location of the train itself.