For anyone looking for a good early warning app for quakes -- I was looking for one first time I visited Taiwan last year, because we use this 24/7 in Japan on cellphones -- to my surprise Namazu Alert
works quite well now even in Taiwan.
To be clear, the app is Japanese and for Japan, but as the Japanese early warning system reaches down all the way to Yaeyama District ( the Okinawan islands just a few km off the coast of Taiwan ) it effectively warns of most quakes that happen in or near Taiwan just as well.
Sure, Taipei is not like Kanto, where everything shakes up, down, and sideways a few times every week -- and you want to know a few seconds in advance if it will be a nasty one or the Tokai bomb we're always waiting for. This might be more useful for those in Hualian and thereabouts, perhaps. In fact all the warnings I get these days are always around Hualian.
Plenty of settings to play with, location, distance, magnitude, alarm, etc. For Taiwan I recommend setting default location to Yaeyama District or Ishigaki Island.