I'm currently running the last few tests to check the queries used to upgrade FishCart 3.05 and 3.7b databases to 3.1
More versions will be added as soon as possible.
This will make it easier to upgrade older carts.
Released 3.1b7 today with a bug fix and a couple of new enhancements to make it easier to control FishCart from the admin pages.
Certitax is on the radar screen as a possible project to make tax calculation more accurate and flexible. With over 21,000 taxing entities in the US and varying rules regarding how tax is charged, merchants need all the help they can get.