can i see matches broadcasted on the Bt Sport Extra channel on the app? If so how?
BT Sport Extra 1 is available as part of the BT Sport Lite package.
BT Sport Extra 1 - 7 are available as part of the BT Sport Pack.
Methods of accessing tend to vary according to which app or player you are using.
Generally the live Extra channel is only available when it is broadcasting so if you select the app's Watch Live options you should see all the available live streams.
I think it varies a bit ... currently I have a 34 second difference (delay) on the BT Sport ESPN Ipad app feed compared with the Youview BT TV channel.