This is similar to another thread, but I just did a comparison of planning sites, using Earl's Court to British Museum as a test. First the comparison:
Google Maps Picadilly to Holborn 26 minutes
Citymapper Picadilly to Holborn 30 minutes
TFL website Picadilly to Russell Square 29 minutes
Moovit District to Embankment, Northern Line to Tottenham Court 33 minutes
My impressions: Google and Citymapper obviously most similar. Using four different sites, was taken to three different tube station as destination. So if you were planning to go to major site, you can either enter that site, or if you were specifically wanting to go to a specific tube station, be sure to enter that tube station as your destination. I was interested in Moovit app because I had read it helped finding best entrances and exits of tube stations, but does not seem as good (or at least does not agree) as other sites/apps. In this particular comparison, you might prefer one over the other because of wanting to use front entrance or entrance on Montague St. Would appreciate others' impressions. Other than a possible preference of stations, and taking into consideration the busy peak travel times, is there anything else that someone might take into consideration when planning a route, or choosing planning site?