In order to debug your android device :
Plug your phone to your PC through USB (be sure to activate USB debug mode on your Android phone) and in the Chrome browser on the PC, reach the URL "chrome://inspect/#devices".
This can allow you to debug a debug APK and see what may be going on.
This should also allow you to see an HTML5 application being executed in a browser.
With the informations provided in the console there is a better chance to investigate what may be going on.
This is like checking for errors in your browser.