To solve the issue of debugging on mobile phones whose OS have limited capability to throw JS console output, and also for a very easy way to check if your app is working correctly, is to add the following line within the <body> of your index.html file:
This will produce a console output on your device screen regardless of it being an iOS or Android device and therefore will give much more clarity at the time of bug finding/fixing. Is good to have this line always included even if it is commented out just for re-testing purposes. Any error output on the console will appear in the screen of the device.
Remember: many cryptic errors can be found using this output, besides providing valuable information about the behavior and performance of your App.