To restore Avaz from iCloud backup, 

  1. On your iOS device, go to Settings > General > Software Update. If a newer version of iOS is available, follow the onscreen instructions to download and install it.

  2. Make sure you have a recent backup to restore from. Go to Settings > iCloud > Storage > Manage Storage (or Settings > iCloud > Storage > Manage Storage), then tap a device listed under Backups to see the date and size of its latest backup.

  3. Go to Settings > General > Reset, then tap “Erase all content and settings.”

  4. On the Apps & Data screen, tap Restore from iCloud Backup, then sign in to iCloud.

  5. Proceed to “Choose backup,” then choose from a list of available backups in iCloud.

For more information, click on the link below: 

iCloud: Restore or set up your iOS device from iCloud