Well I did have a pattern lock so the smudges pretty much gave it away. I’ve changed it to a PIN (takes slightly longer but presumably more secure).
I’ve also added a Norton App lock code to the Monza app.
But this all feels like I’m patching a gaping hole in Monza security - that it’s so easy to find out the pin number.
What really worries me is the comment above about how foolish it is to keep my phone and card together. I now rarely bother taking my wallet out - no need. I take my phone, a card and a small amount of cash. It’s far easier to keep all that together in the mobile phone case. If I keep my card on its own I suspect I’m much more likely to lose it. So now I’m not sure what to do…