When changing device you might want to keep the tones save on your old device and migrate them to your new device! iCloud Backup includes App data so when the feature is enabled the Spark App and its content are saved on Apple Cloud storage.
What you need is to make sure the backup feature is enabled on your mobile device.

How to use iCloud Backup ?

1. Make sure that iCloud Backup is turned on in Settings > [your name] > iCloud > iCloud Backup. If you’re using iOS 10.2 or earlier, go to Settings > iCloud > Backup.
2. Connect your device to a power source.
3. Connect your device to a Wi-Fi network.
4. Make sure that your device’s screen is locked.
5. Check that you have enough available space in iCloud for the backup.

Once your backup is done and on the Cloud, you can use the restore feature on your new device.

Restore from an iCloud backup

1. On your iOS or iPadOS device, go to Settings > General > Software Update. If a newer version of iOS or iPadOS 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 > [your name] > iCloud > Manage Storage > Backups. Then tap a device listed under Backups to see the date and size of its latest backup.For information about backing up manually now, see Back up your iPhone, iPad or iPod touch to iCloud. If you do not see a backup you expected to be there, see the Apple Support article If you can’t back up to iCloud or restore from iCloud backup failed.
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 with your Apple ID.
5. Proceed to “Choose backup”, then choose from a list of available backups in iCloud.

Of course, best is to also save your tones to the Tonecloud!