I just tried the beta version of Taxomate and it worked great. I had no issues setting it up and now it is completely synced up to my QBO account. The quick setup was really a breeze. I really like how the transactions were easily mapped to my Amazon account. I have 4 Amazon marketplaces connected right now and they are working perfectly.
The support was great and answered any questions I had prior to signing up. Highly recommended for any Amazon Seller using QuickBooks Online and no longer wants to manually input.