Click & Drop

Works really well for me. All orders are imported and sends the tracking back to shopify. There's a settings to Mark as Dispatched when you create the label and another to export the tracking number at the same time.

Very occasionally you have to re-link the app on the Click & Drop website, maybe when there's been API changes? It's easy to update but also quite easy to end up duplicating the integration - this is how you get duplicate orders. Just delete the second integration to resolve.

Quietly works in the background without any involvement needed 99% of the time. Excellent.