A2X Sync for QuickBooks & Xero

This app is mission-critical. I use it to generate .iif files to import into QB Desktop for Mac - it's one of the few services that doesn't force you to use QB Online and I really appreciate that! The account mapping takes some patience, but it's well worth the time. We don't use the COGS functionality, but I think that could be helpful for many businesses. Support has been stellar.