Found a simple and accurate online timetable for Mumbai suburban railway network (mumbai local).
It's clean, simple and adfree unlike the many other sites. Hence this one works like butter on a mobile phone browser.
While Mumbai local has a frequency of 3min at peak, this tool will be helpful for planning those early morning or late night trips when the frequency dips.
Smarter still, you now know whether you can avoid that jampacked virar local for the next which could be a less crowded borivili local.