Old town trolley, but I don't think there is much difference, seems they all stop at the same place. There is also a public transportation free bus service which is similar but cant remember the name.
Old town trolly....the main check in place is across the street from fords theater....although you can get on at any stop and pay when u reach the main hub if you don’t already have a voucher.
Old Town Trolley
It was Old Town Trolley. Make sure you start at the designated start points.
Old Town Trolley Tours is the company we used.