Works in Switzerland; Had it with Sunrise and Swisscom, both with eSIM. Reception is slightly better with Swisscom.

This connected watch supports 4G technology with VoLTE, enabling you to make calls in high definition on a 4G network. If the watch is connected to a 4G network and the call is using VoLTE, an "HD" icon will appear on the screen. For the best experience, we recommend using an Xplora Connect subscription or a compatible provider, which includes operators such as Salt that support VoLTE.

Yes

eSIM works perfectly

No, WhatsApp is not available on the Xplora X6 Play or similar models such as the X6 Pro eSIM. However, messages can be sent and received via the Xplora app, including pictures, videos and voice messages.