Invoice Falcon

This company earned 5 star rating, 100%. The team is responsive and as up front about any limitations or flexibilities that exist based on the constraints of the Shopify Platform. I vetted maybe 3 or 4 invoice solutions before I went with Falcon. Use the free trial and you'll probably stick around. If they get it incorporated with the POS checkout, then that would be a game changer. For now you can drop the tile app and use it as a work around. Very happy with the work they did to help customize my needs and grateful I found them on the APP store, keep it up guys!