Useful apps

1. Navigation app: In Korea, Google map will not work. I recommend you to download 'Naver map' app for navigation.

2. Taxi app: Uber works in Korea (note that, unlike the US, Uber only can call a professional taxi driver not a driver who use his/her own car). 

I also recommend you to use `kakao taxi' app. 

Here is a guide to use the app: https://stay.enkor.kr/blog/how-to-avoid-over-charged-using-a-taxi-in-korea-kakao-t