So you’ve moved to town and you don’t have a car, because you want to use public transit. Great! You’ve downloaded a few apps for mass transit around the area and are trying to see when the Green Line will be at your stop. Wait a minute — why do the Red, Orange, and Blue lines have times, but not the Green? That’s because the MBTA has not installed the GPS technology those apps use to calculate your times on the Green Line trolleys just yet.