In uk.transport.buses Paul Corfield wrote:
Although there are some excellent companies and counties who do a
sterling job in keeping bus stop info up to date. You also have a number
of places with real "real time" info systems at stops and accessible via
text. You also have the back up of being able to text for the
theoretical times for next buses in many counties. I once found out how
to do it for TfL's stops and did manage to get the real timetable info
rather than "intervals". In some respects it is London that is behind
many other places.

You can find all the timetabled info from a stop he
http://www.travelineeastanglia.org.uk/
(works for London and SE too)
More - next departures

There's various phone apps for this. When it has live info (such as for
Cambridgeshire), that will be displayed too.

What's the situation with TfL's live bus info feed? It's on the bus screens,
and TfL are usually good about publishing free data. I'm surprised that the
wilds of Cambs have been ahead of the metropolis in this respect.

Theo