As far as I can tell, of the oneworld carriers, BA's app is the only one that shows the flight number, PNR and ticket number all in the one page, without having to click on manage my booking and going through to a browser. Had a check on some of my live bookings on AA, AS, QF, QR and JL. None of them show ticket numbers.

Maybe AY also includes ticket number (I don't have a live AY booking to test)? But I recall the AY app was a little clunky and didn't have a great user experience. Can't recall MH's and UL's app either and no live bookings for those to test. But I don't recall them being particularly usefull.

For all the knocking BA's IT gets, they've done rather well with their app.