This app was mentioned in 1 comment, with an average of 11.00 upvotes
They are the regular metered spots, you just pay w/ the app on your phone instead of putting quarters in the meter... The meters have stickers with a Zone on them, you punch in that zone number (they get very specific; zone 240 is Lincoln Street between Kneeland and Beech) and your license plate # and you're good.
App store link: https://itunes.apple.com/us/app/parkboston/id953579075?mt=8
Android: https://play.google.com/store/apps/details?id=com.passportparking.mobile.parkboston&hl=en
It's called ParkBoston