Q: Just started os7 and cannot find airplay button to connect to appletv

It's set up a little differently. You swipe up to access airplay via control center.

If you're not seeing the airplay icon then it's a network issue

The AirPlay icon in the control centre wasn't visible to me until my battery had a 22% charge. 

Battery life has no bearing on whether the icon appears

I'm just saying that I was fooling around trying to get AirPlay and iOS7 to to work for about an hour, reading all the help forums and the Apple support discussions. Nothing worked. It just happened that I had low battery so I plugged the phone in. Once the battery went over 20%, the AirPlay icon appeared. That's the only thing that was different.

Ok, well it sounded like you were stating that the battery life had some connection to it appearing when it fact it's network related.

Settings, Video, Turn on Home Sharing.

Did the same on my apple tv using the apple tv remote.

Now my control center shows AirPlay

I did need my apple ID and password.

Home sharing is separate, you do need to make sure airplay is enabled on Apple TV though.

I have tried home sharing and still no air play icon. Have spoken to several people all on diff networks and they can contact to any AirPlay device. This is both on my I pad and I phone 5. Before the new update air play was working fine and I had a air play icon.

Is this just a uk fault ??

Home-sharing is a separate feature so it would have no bearing on whether the icon shows up. Have you followed the troubleshooting tips?

http://support.apple.com/kb/TS4215?viewlocale=en_US&locale=en_US