Originally Posted by riku2

I did not understand this either. You can only take part if you have a finnish passport, in which case you can use one of the many automated border control machines.
So instead of doing that you sign up for the app and then must use a single specific manual desk, plus you have to "Send the data from the application to the Finnish Border Guard
36−4 hours before your flight each time you fly from Helsinki Airport on a Finnair flight to London, Manchester or Edinburgh and when you return to Helsinki Airport on Finnair
flight"

So why would I do all this since it does not make things easier for me whatsoever.