COMODITI

Definitely the most comprehensive app for this type of functionality. I needed to apply and remove tags on a timer as well as other triggers besides ordering. This was the only one that could do it. I had a few teething problems get it going but the Customer Service is top notch and they looked into it for me, seems the problems is with Shopify's web-hooks and I'm satisfied that is correct. Definitely the app to install if you need to auto tag customers.