Backtrack BART is an app built for frequent BART travelers, for old and young. You might be using the BART to go to your workplace and back. If you are traveling during peak times it will be crowded and chances of getting a seat is less. You might even end up standing in long queues.
Traveling backwards by a station or two will help you to get a seat to your destination on the BART that you want to travel.
Using Backtrack BART will allow you to select your From/To route, select the time of travel and view how many stations you can go backwards to catch the same BART that you want to travel to your destination.
Go ahead and make use of this service. it should be of great help for you guys in SFO.