You can access PikTV through the PikTV device, Nvidia Shield, AppleTV, and iOS and Android Apps, and web browser. If your iPhone and iPad apps are not working, try deleting them and reinstalling.
The iPad app is working for me.
The Apple TV app is just that an app, it's totally different from Apple TVos which PikTV does have an app for. What apple devices are you using? Generally you delete the app, Reboot the phone (turn off and back on) then reinstall the App. Have you rebooted the device after you removed the app?
If on a home computer asking PikTV via a browser make sure you delete ALL cache and follow this link http://www.telus.com/watchpik
What you're seeing on your iOS device and Apple TV app is the integration of the Pik TV app into Apple's universal services - this includes things like zero sign on and Siri search. This integration allows you to watch authorized apps like Pik within the Apple TV app. One caveat to this, though, is that an app needs to be available for that device, and then installed on that device. If it's not - the integration isn't possible.
Example: Pik app is available in App Store and can be installed on an iOS device - so it can be integrated into Apple TV app.
But, the Pik app is not available for Play Station - so cannot be integrated into the PS Apple TV app.