ZeTime is an hybrid smartwatch (with both screen and hands). Its official app is not open source, and there is no documentation on the protocol used.
I have started reverse-engineering the protocol (see this file), but it's far from finished. I will try to complete this protocol description over time, but I am not a BLE expert... Also, while I have already developped a couple apps, I am not an Android developper.
This issue is just here in order to find other interessed people, who have a ZeTime, some time and Android developpment knowledge.