If you are seeing a popup labelled "Cloud backup failed" appear at the top of the game's screen, this is an indication that your device is not using a cloud backup, which puts your game progress at risk of being lost.

For iOS we use iCloud Drive for saving game progress.

Follow these steps to ensure your backup is working correctly:
1.  Go to the Settings app
2.  Make sure you are signed in to your Apple ID
3.  Once signed in to Apple ID, make sure iCloud is enabled
4.  Go into your iCloud settings and make sure both iCloud Drive and Jetpack Joyride are enabled