This guide is an overview of Digium Phone app development: the process of building an app, reviewing and testing it on the phone, and the basic development tools.
What You Need First
Digium Phone dedicated for development, on a trusted network
Digium Phone firmware version 1.3 or later on your phone (download)
Building and Reviewing a Custom App
Browse the API Reference and the Demos sections to familarize yourself with the phone API.
Write your app.json file, ensuring it has all the required information.
Enable App Development on your Digium Phone.
Add your app's zip file to the phone using the phone's app development tools (web page or the CGI).
View the Debug Log to be sure you don't miss any problems. See util.debug for more information.
Start your app, and run through its features.
Repeat as necessary. When you make changes, remember to zip the files again, upload the revised zip file, view the log, and start your app.