The development of hybrid app using third party tools such as Secha or phonegap (cordova) was included from SUP version 2.2. It gives the developer more control over the application. Since you are using 2.1.3 you can make use of phonegap and custom.js to satisfy the requirement.
For customization (limited) HWC comes with a file "custom.js" where custom code can be written to get a better UI. The phonegap plugins comes with HWC hence barcode reader can be included with the app. Examples given below helps you to use the native features of phone using phonegap:
Adding some Phonegap Plugin in the Workflow (HWC)
Hybrid Web Container with Camera, Network and Location Base
Barcode scanner in iOS for HWC
I have an example where I uses filtering of a list, Developing HWC app with Customized List
Midhun VP