Easiest way to get an alarm on my phone when sensor is tripped?

A function that is available in one smartapp is not necessarily available in another.

Try it out and let us know.

Also, I’m still unsure that we’re understanding each other re: the difference between officially published smartapps that you can tap to install from the marketplace tab in the ST mobile app, and community developed code that you must add by logging into the Integrated Development Environment from a web browser. Here is an FAQ post about custom code.