Hello AngusW and others. I just started using an iPhone 5 recently (about 2 weeks into it) and updated to the latest iOS 8.2 which fixed a number of issues with 8.1.3 and previous versions. I then purchased a UWatch U Terra. I am really excited about using this with my iPhone and Hopefully this is similar enough to other UWatches like the U8 UWatch. My experience so far (just got the UWatch today):
* Out of the box, the UWatch will control the phone's call and answer functions, allows sync with the phone book contacts, allows music to be played once the player is enabled on the phone...that's about it.
* After some examination of various help information on the Apple website and various forums, I figured out that if I enable SMS messaging on the iPhone under settings-Messages-"Send as SMS", then I do get notification that a message has been received by the phone...one little thing done!
* After another couple hours of persistent searching through the internet, I ran across an obscure message from a chat forum and on the www.gearbest.com website that sells similar UWatches: go to the App Store and download/install "Mediatek Device". This application looks as if it just enables workout tracking data to and from the watch and iPhone, but it ALSO enables SMS messages to appear on the phone so they can be read. There seems to be some functional issues with the message app on the phone retaining these, but at least they are notified and can be read without having to get out the phone!
* The Mediatek Device App also enables the control of the iPhone camera once the camera is turned on at the iPhone. Shutter control only as far as I can tell, but that's all I really need.
I also played around with the App other people have mentioned called "UWatch" at the App Store. This App has a really good interface, but seems non-functional with my setup...and apparently with most of the other users who have tried it. I hope that the developer can make a few upgrades and really enhance the UWatch experience for everyone.
Hope this is helpful to all. Best of Luck!