Comment by ale42

This is using Twilio, but given there's an Asterisk server behind, you can actually use any VoIP provider that allows outgoing calls over SIP right? Depending on the country you live in and/or where you want to call, you might get simpler & cheaper options (although for emergency service if you want to have it, which I think is important unless there's an alternative way to call emergencies around, it's more complicated).