This is a countdown clock app using the MTA GTFS API. Yay
Here are some helpful links:
MTA Feed Ids https://datamine.mta.info/list-of-feeds
MTA Stop Ids http://web.mta.info/developers/data/nyct/subway/google_transit.zip
Franklin Ave Subway stop: 239N && 239S
GreenPoint Ave Subway stop: G26N && G26S