Barcode Box 2 — Open Source Media Player App

You will need https://f-droid.org/packages/com.google.zxing.client.android to be installed. Records a list of barcodes when you scan them and reminds you if you've seen it before. Useful for remembering which books you've read or things you've seen in the shop. It features a rapid scanning mode, and allows to export the history of barcodes to CSV.