I just bought my bosses Moto 360. I'm still using an iPhone 6+ until the end of the month- can I use the watch at all?
You could only use it as a regular watch and with the built in faces... not much customization you can do there, unfortunately. These devices are designed to work paired with an Android phone. You use the phone to customize the watchfaces (yes, even the built-in ones), push notifications, and even set the time on the watch.
You'd need an Android phone to do the initial set up, but after that, as long as you keep to the built in faces (as previously customized on the Android phone), you can still use the watch as, well, a watch. It'd just tell time and you could only swap the preloaded, pre-customized watchfaces.