Any barcode scanner should work with WooCommerce POS, scanners simply output the serial number to the computer just like a (really fast) keyboard. For more information about how to set and search barcodes in WooCommerce POS, please read the Barcode Scanning documentation.
Version 0.4 of WooCommerce POS will support hotkeys - this means that if you set a custom prefix on the barcode scanner the POS will automatically know you are scanning a product without having to manually focus on the search field. For this functionality to work you may need a scanner that supports 'custom prefixes'.
For a good general purpose barcode scanner that works well with most devices we recommend the TaoTronics TT-BS016 Bluetooth Wireless Barcode Scanner. However, you should read the capabilities to make sure this scanner is suitable for your requirements.
For other barcode scanner recommendations please read the reviews below: