I purchased this app today. Karol was very helpful and walked me through my initial sync. It was very easy and will make my job easier. Thanks again Karol for your assistance today! :)
Had an issue with items syncing today and spoke with Haze. Told me what the errors were and corrected them for me. I was back up and running within minutes.

Karol with chat support was awesome in helping me fix my errors. She made my mistake and correction a lot easier and was very attentive and fast. Great support!

Online support from Francois has been amazing - instant response, and able to fix all my sync issues!

I really appreciated the follow up and follow through and help I received from Hazel in clearing up the syncing errors that occurred between Shopify and Quickbooks Online. She was thorough and complete and responsive.

While the app wasn't quite right for our company's needs, the support we received while testing was exemplary. Hazel, Marck and Vincent were terrific!

App works well for Shopify to QBO. Had a hiccup in syncing, and asked OneSAAS for support by email. Hazel got back to me quickly with a fix.
Would rate app 5 star -- but have to take 1 star off for the fact the sync stopped working for no reason, and required an intervention to fix.

App does just what I need it too - all my sales chanels are synced :) Really helpful customer support. That's always good. Thanks Hazel!

EDIT 5/27/19: The refunds issue has been fixed. However, there is still a bit of manual entry as the software is unable to determine if an item was restocked in Shopify, so it defaults to 1) restocking the item if all money was refunded or 2) only returning the money (and not the product) if only a portion was refunded. Still a great interface, but a bit cumbersome if you offer a "money back guarantee" or any instance where the product would be kept when funds are refunded. Still can't say enough about the level of service and follow-through from the team: Hazel, Troy, Vincent, and Marck - they are all amazing!!
---
EDIT 4/23/19: While I still think this is a great app, they still have not been able to fix a bug that prevents refunds from posting to QBO. This has prevented 186 transactions and required me to hand key each and every one. I/They have been aware of the issue for 2 months and there is no timeline as to when this will be resolved. I will update this review when it's been fixed.

----
Best app on the market - hands down! I tested several for my clients and landed on OneSaas for their seamless automation and easy but robust setup. As an accountant I love all the options they provide (chart of accounts mapping, seamlessly adding new inventory items into QBO, inventory update sync, etc.) as it makes my life a whole lot easier.

The best part; however, is the AMAZING customer support team. I've had a few bumps along the road and they have been there to quickly and efficiently handle every situation I've thrown at them. I think I've spoken with almost the entire support staff, but mostly I've chatted with Troy and Hazel. They are very friendly, knowledgeable, and often go out of their way to ensure everything is handled quickly.

Stop considering and just do it. You won't be sorry.

App has freed up a lot of labour hours.
Very responsive staff when you have technical problems as well. Marcks been a champ.

Works perfectly, OneSaas support are helpful. Only limitation that we found annoying was you can't set up a workflow where OneSaas tries to push an order from Shopify to your accounting system (Saasu in our case) as a Tax Invoice first, then if stock is not available (negative value) then it will push it through as a Sale Order. You can only choose either to sync all orders as Tax Invoices or Sale Orders. Then you either have to go into our accounting software and manually change all the orders into Tax Invoices or wait for pre-ordered stock to arrive before OneSaas will push the orders into Saasu as Tax Invoices. Would give 5/5 if this became a feature.