Awesome! There's a slight delay with no loading animation in between when the barcode app closes and when the isbn gets inserted that is just a little too long for no feedback on my phone... is there any way to make that pending? And also, when you press back after denying camera access, you get an empty dialog. But yes ship it :D.
I note the small camera icon in the top left of the system tray disappears at the same time as the barcode appears. I would suspect that the camera closing is causes the whole phone to freeze up for a second. Potentially we could emit the barcode detected event before closing the camera so at least the code is there when the phone freezes.