In order to recover progress in Fruit Ninja, the process is different depending on your platform. iOS or Android.
Android Devices:
On Android, we use Google Play Games to sync your data online. This means you can find it on any phone by simply keeping signed in to the game account on any device you play on. You can confirm if you're signed in on the settings menu of the game.
If you see "sign out" on this screen, it means you are signed in and good to go.
If you're signed in to Google Play and are still missing progress, please contact us.
Apple Devices:
For Apple devices, we do not currently have a cloud backup system for data. If you would like to recover missing progress, then please contact our team through the "Help & Support" button in the settings menu.