Q: I've lost Airplay on iPad and iPhone 5s since 7.1 upgrade

You should check if your iPad/iPhone has lost connection to your WiFi.

Sometimes after an update your iPhone/iPad will have to manually be reconnected to your WiFi.
AirPlay only appears when connected to the same WiFi as for example a speaker.

If your iPhone/iPad still won't show the AirPlay icon I suggest you do a reboot of your device by turning it off and back on.

Hopefully this will help you.

iOS: Use AirPlay Mirroring

http://support.apple.com/kb/ht5209

iOS: Use AirPlay to wirelessly stream content

http://support.apple.com/kb/ht4437

iOS: Troubleshooting AirPlay and AirPlay Mirroring

http://support.apple.com/kb/TS4215

Controlling who can AirPlay to your Apple TV

http://www.ilounge.com/index.php/tips/comments/controlling-who-can-airplay-to-yo ur-apple-tv/

How to Fix: AirPlay Icon Missing

http://ipad.about.com/od/iPad_Troubleshooting/a/How-To-Fix-Airplay-Icon-Missing. htm

AirPlay Icon Missing in Control Center

http://appletv2.com/airplay-icon-missing-ios-7/

 Cheers, Tom