Shopsavvy finds almost all the electronics you can scan. The price comparisons are good too. The killer features is the alerts though. Be sure to use it during christmas shopping!
Compare everywhere finds more house hold items than shop savvy. Jam jars, soups, coke cans, it can find anything. A tad slower than shopsavvy though.
Barcode scanner performed the worst. It needs an improved barcode database.
With the competition starting to heat up among android apps, the app that provides the most open data with spam prevention and data cleaning features would be the winner. Think wikipedia, not microsoft office.