"Game constantly crashes on older I Phones"

#PokemonGO: In the past month it has been increasingly difficult for my sons to play Pokemon Go on their older iPhones. (iPhone 5s and iPhone 6+)When they try to add a Pokemon to a gym or berry a Pokemon on a gym the app crashes. When they try to initiate a trade the app crashes. Often when they try to transfer a Pokemon to the Professor, the app crashes.This is not due to weak internet because even when sitting at home in front of the wifi router the crash issues are the same. Deleting the app and re-installing has not helped. Removing all pictures from the phones to free up space has not helped. Re-booting the phones has not helped.They are not alone. Other players with older iPhones have also commented that they get app crashes much more frequently.Is there any solution? One son has been playing since 7/7/2016, but is ready to quit.The other apps on the phones work fine e.g. mail, maps, weather, news, etc. via /r/TheSilphRoad https://ift.tt/30GJegz