South Korea

⚠️

Apple Pay / Google Pay

Use instead: T-money card

🟡Local app preferred

Contactless cards work in chains; get a T-money card for buses/subway and carry some cash for small shops.

✅

WhatsApp

Use instead: KakaoTalk

🟢Works fine

WhatsApp works, but almost everyone uses KakaoTalk; install it to reach hosts, guides and services.

⚠️

Google Maps

Use instead: Naver Map / KakaoMap

🟠Unreliable

Google Maps has almost no car navigation in South Korea (a data-export law); use Naver Map or KakaoMap for driving and transit.

⚠️

Uber

Use instead: Kakao T

🟡Local app preferred

Uber runs as 'Uber Taxi', but Kakao T is the dominant app for hailing taxis.

US roaming works but is expensive; a local eSIM is cheaper and faster. Set it up before you land.

✅

Instagram / Facebook / X

No direct substitute

🟢Works fine

US social apps work normally.