Highly recommend everyone look at QPOSConnect - this app is the solution I've been waiting for for 5+ years. It connects existing POS to a QBO account (i simply uploaded by QBdesktop data to QBO) and now I'm in the cloud for all bookkeeping. At Last!!!
The QPOSConnect team was admittedly a little hard to reach at first - make a trial account and then chat within the app and they responded quickly and got me all set up. They're also willing to add other features, nothing I needed right away, but it was nice to know they were willing to look at our needs.