This is the best barcode alarm I could find, and it’s working well for me, but it has two significant drawbacks:
1) You can’t set alarms to go off on only certain days of the week
2) You must manually reset the alarms every day or they won’t go off
Having said that, it’s a solid, stable, and functional app, and NO, you can’t silence it by swiping up on the app-management screen to close it, which is crucial.
Brian956 about Barcode Alarm Clock