1- Before activating iCloud Sync we recommend to do a backup using Dropbox just to be on the safe side.
2- After purchasing the iCloud Sync feature, enable iCloud in the Settings on your main device eg. your iPhone.
3- Tap “Backup to iCloud”. Now the iCloud contains your latest data. Remember you need to do this only the first time you activate your iCloud. If you choose the second option, all your local data will be wiped off and replaced with the iCloud data so caution is advised.
4- On your secondary devices like iPad, iPod Touch or another iPhone tap on the “Restore Purchases” you get after clicking the big blue rectangle in the Settings. Please remember that in order to successfully restore purchases on your devices you need to be logged in with the same Apple ID as in your main device.
5- After restoring the purchases on your secondary device you can activate iCloud on the Settings tab. Select the second option “Restore from iCloud” to sync your latest data. Remember that if you select the first option, all of your saved iCloud data
will be wipped off so caution is advised!
6- You can repeat this process for every secondary device you have. Once activated, all your devices sync automatically and all your data is available on all your devices. The data available on your Apple Watch gets synced via your main iPhone.