Hi , hope you are well
I have experience in ChromisPos ,Unicenta and Openbravo POS , Floreant POS
here is my old projects on freelancer.com for POS
https://www.freelancer.com/projects/Software-Architecture/Tweak-Discount-script-for-Unicenta/
https://www.freelancer.com/projects/openbravo/OpenBravo-Pos-Customization/
https://www.freelancer.com/projects/php/simple-POS-edit/
i am java developer and i have 5 years experience in software development for ERP system and Point of sales open sources
i read your project description and wait to discuss with you the project requirements
you can check my profile and my customer review specially for POS projects , i keep my credit to keep my client satisfy about their results
hope to contact me to discuss more about your requirements
Thanks