I asked for a similar question some months ago, here the answer I've had:
"All APIs are functional even without a license key. The term 'requires a RhoElements license" identifies which APIs are licensable. Apps are fully functionable without a license so to faciliate the developmet, testing and debugging, though with the nag screen. One can purchase the physical license key once ready for production deployment.."
This is the thread: https://developer.motorolasolutions.com/message/8473#8473
In order to build barcode you need to install rhoelements gem (even if no 'app_type: rhoelements' at your build.yml).
Without a license it will display a license alert at application startup.
- To answer your question, It is possible to use Barcode and Signature capture in your application, it will be fully functional without RhoElements license for development and testing purpose, though you will see a non-licensed message on startup on other devices and Motorola solution devices will display a periodic nag screen.
- When your application ready to go live you need to purchase Rhoelements license.
- Please refer this link for more details related to RhoElements Licensing.