Hi @Brian_Carpenter,
Nothing really special. You need a notification service; i use pushover.net but you may use anyone like signals/twilio.
You create device(s) that will receive the notification, in the notification service backend.
Then, you install the app on your device. And in your ignition project, just create a script like this one (for pushover):
#notify mobile using Pushover service
url = "https://api.pushover.net/1/messages.json"
contentType = "application/json"
brutData = {
"token": "Blah blah",
"user": "Blah blah",
"device": "gng-ipx",
"title": "Ignition",
"message": "Notification service is live!"}
postData = jsonString = system.util.jsonEncode(brutData)
result = system.net.httpPost(url, contentType, postData)
Token, user, device are coming from the notification backend service.
Hope this help.