Which countries can use this exchange? Often there are a lot of excluded countries.
None dev team can give you exact list of excluded countries because the list of them is constantly updating.
It's not devs who exclude countries from participating. So you'd better consult your local lawyer to make sure that your country is restricting/not restricting crypto usage. This will be the best way to find it out.
Devs, do you already have a demo platform or demo wallet?