To search you press the menu, select search, select search by name (not the top item), get a box called "filter" with an almost invisible search button and where enter does not do a search. If it doesn't find any matches it just leaves a blank screen as if nothing has happened. Oh and if you pressed return first it wont find anything as the carriage return is part of the query so it doesn't match.

When I finally get the results of my query for "Hammersmith" it tells me that 309km away (some mistake, more like 3.9km) there is "Subway Station District Line;Hammersmith & City Line", and then the same result repeated around 150 times some with slightly different naming, and at varying distances from 309-328km away before it gets to other results in Hammersmith.

And you are trying to use this on a phone in the rain, you just give up and go back to google maps even though the data is worse.

EDIT: And if you select one of these it appears to be in Barking, as it found every station on the Hammersmith and City Line, although that is not 300km long.