Can you delete it by going to >General>Usage>Storage>Manage Storage> The app?
- Reset the iOS device. Nothing will be lost
Reset iOS device: Hold down the On/Off button and the Home button at the same time for at
least ten seconds, until the Apple logo appears.
- Tru deleting from Settings>General>Usage>Storage>Manage Storage>the app in question
- Reset all settings
Go to Settings > General > Reset and tap Reset All Settings.
All your preferences and settings are reset. Information (such as contacts and calendars) and media (such as songs and videos) aren’t affected.
- Backup and restore restore from backup. See:
iOS: Back up and restore your iOS device with iCloud or iTunes