Pokémon GO will drop support for older iOS devices
iPhone 5/5c models and up to 4th generation iPads are among those that will be impacted by the end of February.
Niantic, the development team behind Pokémon GO, have announced that they will drop support for older iOS devices by the end of February.
Trainers, some improvements are being made to Pokémon GO that will impact gameplay on Apple devices which are not capable of upgrading to iOS 11. Learn more here: https://t.co/C7I6V3wtCr
— Pokémon GO (@PokemonGoApp) January 10, 2018
In an upcoming update to Pokémon GO, we will end support for Apple devices not capable of upgrading to iOS 11, such as iPhone 5 and iPhone 5c models. This change is a result of improvements to Pokémon GO that push the application beyond the capabilities of the operating systems on such devices. This change will take effect on 02/28/2018. After that date, Trainers using affected devices may no longer be able to access their Pokémon GO accounts from that device, or use their PokéCoins or other items in their Bags. They will need to switch to a supported device to continue playing Pokémon GO. You can see the full list of impacted devices and learn more by visiting our Help Center.
The iPhone 5, iPhone 5c and 1st to 4th generation iPads are listed as affected. Supposedly the reason these devices are being dropped is that they run on 32-bit processors, rather than 64-bit processors found in newer Apple devices. The breakdown of usage of Apple devices is given below.

No mention of dropped support for Android phones have been yet made.
Will this drop in support affect you?
Edited by Jake, rainbow and Zach.