When the "app immediately closes" it's usually caused by the program crashing.
The channel list has never crashed for me, so I'm whistling in the dark here.
No answers at this point, not even guesses, just a few questions.
Do you have all the channels showing in the Channels list (there are 70)?
Have you tried hiding some of them (Edit - tap the red dot)?
Is there a subset of channels that does not cause a crash.
There's always the "Delete the app and reinstall it" gambit.