We're currently deploying a FileMaker Go solution for a customer that uses a Captuvo SL22 jacket with an iPod Touch for scanning barcodes into a database. The Captuvo can't interface with FileMaker Go directly without a third-party app. There are 2 free ones that we're trying, HID Switcher and SLWedge (Japanese).
The HIDSwitcher app allows you to turn the jacket on and off. Turn it on and you can scan into any field in any app on the device. However, the soft keyboard is not displayed while the jacket is turned on so you can't enter anything by hand, although we've found that the 10-key and telephone keypads can still be displayed in FMGo.
SLWedge is a keyboard app. You can scan codes into any field when the SLWedge keyboard is selected. The keyboard is a little clunky but might be better than nothing when you need to enter a code by hand.
Your question is a little old but if you're still looking I hope that helps.