FYI, most barcode readers just “type” the keys into the keyboard buffer or HID. You could literally just have a text input box (that honors enter key) to make it barcode enabled. Of course x-reference this info with something like the “what” database and you’d have great input.
I recall the "zbar" library being (relatively) easy to integrate and working damn well out of the box, on both iOS and Android, back in 2011 or 2012. I'd expect it's gotten even easier, if anything. It's been a while but IIRC you just find a way to hand it bitmaps from your camera, and it does the rest, spotting and decoding QR and bar codes.
