Crosscall CORE-S4 runs KaiOS and it's supported by PhoneCopy.
KaiOS helps to offer smart features on the most simple mobile phones. Similarly like on the smartphones you can download applications from the application store named KaiStore directly to your phone. When you buy a new phone you need to transfer your personal data from the old phone before you start to use it. This is a reason why PhoneCopy should be the very first application on your phone. Later you can use it to back up your contacts and photos to keep it safe in the case when your phone is lost or damaged.
With PhoneCopy you can easily transfer your contacts and photos to any other phone and it doesn't matter if it is a smartphone or feature phone. It takes a few seconds and you can call your business partners or friends again.
How to synchronize contacts to KaiOS
How to backup contacts from KaiOS
How to synchronize calendar with KaiOS