There are several watches out already that sync with the iPhone. Not having any experience with the others, I can't post on their functionality but I can attest to the abilities of the MetaWatch. I have had the MetaWatch Strata model since it's release almost a year ago. Initially there were issues with limited functions with iOS when compared to Android. With the release of iOS 7, I now have notifications of everything I want. I currently get alerts with previews of my Exchange Emails, Exchange Calendar events, Twitter posts, Caller ID, iMessages and SMS, Reminders, FaceTime and so on. The battery lasts about 3 - 4 days and charging is via USB and a clip for the watch. There are four display screens that can display different combinations of information including Time, Weather, and Calendar views. I am still looking forward to a Apple version but, IMHO, the MetaWatch is almost exactly what I am looking for in a smart watch.