Evernote on iPhone 5s with iOS 8.1.1 was not syncing (stuck in downloading headers at 85%). Killing the app by app switcher did not solve this. Switching off and on the iPhone completely (keeping pushed the power button until it asks) did solve this : Evernote launched and completed the sync. No more stuck since yesterday (used and synced at least ten times since). So maybe there is some bug with iOS 8 going on ?