@Dany *******
you can't setup scan pay without a Thai bank account. We tried true money when we got here in Dec and we couldn't link any US bank accounts (unless that's changed).
We have bank accounts that refund ATM fees, and CC are taken in a lot of spots (more than I had imagined). So we get along fine until my work visa is approved and I can get my Thai account. But the atm thing is kinda rare for people, so that isn't as convenient for most.
I've lived in BKK and Pattaya the last 5 months, it's definitely plenty safe to walk around with a week ot two's worth of money. But for many tourist who can't recognize the bills, an app would be far more easy and cheaper. My first month here it wasn't uncommon to mix up a 100 and a 1000B bill at quick glance.
It would just be helpful, I don't think it should stop anyone from visiting, long or short term though.