Some reviews on the Play Store complain of internet issues, but overall rating is really good, so I plan to try it out. The price of Chunghwa directly is like 2x as much.
Here’s another thread: Circles.Life Taiwan - #9 by strung.in
The problem is you need to use the app to activate the sim card, and the app is region-locked to TW google accounts. I don’t want to change my google account from US to TW cause you can’t change back for a long time.
I think you can side-load the APK