Niantic just announced that Pokemon GO (Free) will be discontinued next month for iOS devices that cannot be updated to iOS 11. This will be implemented in an update to the app that will happen in the future. Pokémon GO has been pushing for new hardware specific features like the AR mode and they want to push further bringing improvements that require dropping support on earlier versions of iOS. Over the last year, we’ve seen dynamic weather and more come to Pokémon GO and I’m excited to see where the team takes the app going forward.
The deadline for them dropping support is February 28th and after that Trainers may not be able to access their Pokémon GO accounts from the devices that are not supported. To continue playing, you will need to move to a supported device. The devices affected by this change are iPhone 5, iPhone 5c, iPad (3rd Generation), iPad (4th Generation), iPad mini (1st Generation), and iPad 2. If you’re on one of those devices and still play Pokémon GO regularly, you have over a month to upgrade to newer hardware. It isn’t uncommon for service based and living games to drop support for older devices across platforms so this was to be expected. Check out our forum thread for Pokémon GO here.
Update: Niantic has further clarified this new policy-
Actually, Trainers will still be able to play the game using iOS 9 and above. The device must be compatible with iOS 11, but it doesn't need to be upgraded to iOS 11 at this point. For more information: https://t.co/1Xv2XOyf8d
— Niantic Support (@NianticHelp) January 10, 2018