We are getting asked a lot on this question, especially before making the purchase. The answer is:
Firewalla is NOT bound to any geo location. So far, we have customers around the world using Firewalla (running in 60 countries).
Whether Firewalla will work for you or not, it highly depends on the router you have. It doesn't matter how do you access the internet (wired, wireless, or SIM card), you need to have a router. The router needs to have a LAN ethernet port, Firewalla needs to attach to that LAN port to monitor traffic.
Firewalla works with most of the routers out there. But we do know some routers have compatibility issue with Firewalla's simple mode or DHCP mode. Checkout the following list for details: