Debugging Your App
Debugging your app can happen in a few different ways.
Javascript errors can be found in the browser preview using your web inspector. Other errors may require USB debugging on your device.
Debugging in the Browser Preview
The first thing to do is open your web inspector when looking at your app preview.
In Chrome, you can open the web inspector under View => Developer => Developer Tools, or press ALT CMD I.
In Safari you need to first enable the web inspector, then find it in the developer menu or press ALT CMD I.
Click the "Console" tab to see any Javascript errors.
Major errors will appear with a red highlight, yellow and white are just informational messages.
Not all problems with your app can be found in this web inspector, it's better to use USB debugging on a device whenever possible.
USB Debugging on a Device
USB debugging allows you to connect your device to your computer with a USB cable while your app is running, then view errors in a browser inspector.
The browser inspector is the same one you used above to debug the app preview, but you have to use your device as the target.
See: Mobile Debugging for a full guide on connecting to your device for debugging