Ethereum

email is better than all the other chat apps

ethereum is email. global, canonical & you can build on it without asking.

notice how per-company, per-country chat apps (and their various proprietary app ecosystems) come and go, but email is forever. it's been around 60 years and will be around another 600.

Daimo Pay. Build once, distribute everywhere

you have to ask actually

I tried setting up one for myself, got banned by trying to send a message to my own email. this is a protection against spammers who spin up servers with spam scripts. even if you're not, high chances are it won't work

with e-mail your server has to have a good reputation from the start, so you definitely have to ask