I was under the impression that some apps on iPhone 5 wouldn't work, because they constantly come up with newer version of Apps that are heavier and require the latest iOS to run, and eventually the a compatible app wouldn't be available for download anymore because the only downloadable app would say "your iOS is incompatible with this app. Please upgrade" but then iPhone 5 not be able to upgrade to that iOS or even if it can it might cause heating issues or become slow.