I don’t want to spoil this. If you’ve got an iOS device (have not yet been able to make this work on my Mac):

– Download the linked Speed Test app from the App Store
– Launch the app
– You should see a big Go button

Now, before you go any further, let me put out this caveat: If you hate jump scares, even gentle ones, go no further. With that in mind:

– Press and hold the Go button. Don’t let go

You should feel the occasional tap, occurring more and more frequently. Then a bit of a light show. Keep pressing.

Amazing to see the amount of work that must have gone into this incredibly hidden feature. Well done.