I’m having a very small issue with the Unified API
You can get arrivals from the system using
Which is the same as departures for most stops. Except the terminal stops - Stratford Jubilee Line for example. The actual platform has a screen showing them.
Also you don’t get predictions near the start of the line until the train has left the starting station. So the predictions for a station like Hornchurch are very limited in the API.