Chrome Developer Tools
Once your app is running, start Chrome and connect to chrome://inspect/#devices.
You will see all the available Devices you can connect to. Choose Tabris.js (the one powered by Stetho). This starts DevTools.
With DevTools you can set breakpoints, step through functions, navigate the call stack, inspect variables and more.
You can set breakpoints by double clicking in the margin. Breakpoints can then be managed in the Breakpoint view on the right. You can step over, step into and step out of functions:
Using the Scope Variable View, you can browse the variables in all the available scopes:
And the Call Stack View provides you with the ability to navigate the current call stack.
With Tabris.js, not only can you develop kick-ass, cross-platform, mobile apps, but you can develop them — and debug them — at breakneck speed.
Good luck, and happy debugging.