There's a photo opportunity for folks such as you, a luggage trolley going through the wall, labelled platform 9 3/4, right at the far end of the new concourse at Kings Cross.
Very handy for the Parcels Office pub too.

After reading this, I downloaded the London Transport Planner app (I assume that's the one you're talking about?) ahead of the cup final. It seems to disagree with google maps

For example, going from Osterley Park Hotel (TW7 5NA) to Wembley Stadium at 11am.

1 hour 16 mins journey according to rlgoogle mapsrl - H91 bus to Gunnersbury, train to Wembley Central (change at Wilsden Junction). It then says to get a bus to the stadium but I'm guessing it's walking distance.

According to the app it takes 1 hour 34mins - Walk to Syon Rail Station, train to Wembley Park (changing at Vauxhall Underground then Green Park then Finchley)

I'm not sure which to trust now. Is this because the app knows about upcoming engineering works, or does it not have as much information at its disposal as google?

For those who helped me with the congestion charge thing, I still have not received anything from TfL so fingers crossed I'm in the clear now and I was told I would hear within seven days.