Honestly I'd love if more companies could adopt their payment model. Phreeli looks like a solid cellular provider and I'm sure their double-blind armadillo thing is legit, but if I could just mail them an unmarked envelope with nothing but a numeric account identifier and some cash I'd like it way more. Same with Tuta. But I understand there's some possibility for logistical concerns there (what happens if the user loses their account identifier? Too many banks still use SMS 2FA, etc. etc.).