The official London travel app, TfL Go, is outperformed by Google Maps when providing data about how busy transport services are, a review has found.
London TravelWatch rated five popular apps on criteria including crowding.
Such apps are expected to be used by greater numbers as commuters try to maintain social distancing when they return to work following lockdown.
Those three gave no indication at all about how busy services were.
'Falls well short'
London TravelWatch director Emma Gibson said her organisation was "really surprised" that Google Maps came out top in terms of telling people how busy their train or Tube would be.
She said: "Most people would assume that the TfL Go app would have all the information they need to plan a journey which avoids crowded stations and busy trains, but their app falls well short.
"TfL need to have the money made available to them to run the same frequency of services, so that people have the maximum chance to socially distance."
In response, the head of digital at TfL, Ben Gammon, said that since TfL Go was launched in the summer of last year, the organisation had been working to add further improvements.
"In the coming weeks, we will be updating the data source for quieter times to come from our depersonalised wi-fi data at London Underground stations, which will allow the app to more accurately indicate when stations start getting busy.
"We also plan to add real-time status (quiet, busy and very busy) to TfL Go later this summer, helping customers to travel during quieter times and feel confident travelling on our network."
London TravelWatch is the operating name for the London Transport Users Committee, the official watchdog representing the interests of transport users in and around London.
It is funded by the London Assembly, which is part of the Greater London Authority.