I use Go Payment by Intuit very similar to a square reader. As far as I know they don't have an anti gun policy.
I use Intuit, but it looks like I'll have to dump them.
After reading their list, I'm wondering what it CAN be used for. Chewing gum?
Political contributions to the right (oops) correct party.
The other thing we can do is stop patronizing businesses that use square to process payments and let them know why. We don't want any of our money going to their credit card processor. We can force non-firearm businesses to cancel as well.
This!