Incompatible with iPhone 3 / iOS 6

Unfortunately this app requires iOS 7, which runs on iPhone 4 and above, therefore it is incompatible with iPhone 3 that cannot run iOS 7. This surprises me because I have apps from other airlines (BA, Air France, Norwegian) installed on my iPhone 3. KLM check-in opens 30 hours before the flight (unlike for example Jet-2 that allows check-in one month before the flight). If I am travelling then I do not always have access to a printer 30 hours before my flight, so I had hoped to be able to check-in to my KLM flights using my iPhone and store the boarding pass in PassBook. Unfortunately I would have to upgrade my iPhone to be able to do that. I wish that KLM had left the app backward compatible with iOS 6. For the time being I will have to continue to print my KLM boarding passes on to paper.

sopranome123 about KLM - Book a flight, v4.7.4