It would be interesting to see if some of the earthquake advanced warning notifications could be integrated too. at least then it would be an "official" warning. seems like false positives would be possible with the device's motion sensors even with an "i'm okay" type of cancel.
I LOVE this. Thank you! Huge +1, even though it's not going to be easy.
Yeah, false positives are the largest problem. The barometer sensor helps reduce them, but it's not available on all phones.
Machine learning can help a lot here, but I haven't looked for publicly available data yet.