Never miss an urgent call because of your ringer was on silent. Add the number of a contact (spouse, parent, sibling, friend) and if you miss a call from them, it will turn the ringer up so if they call again, you will hear it.
If
Incoming phone call from a specific number missed
This Trigger fires every time you miss a phone call on your Android device from a number you specify.
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Explore more great ways to automate Android Device and Android Phone Call