Clean pos is a open source point of sale you can download and free for modify a codding with your experiment for business,develope with mysql & php for build this application software point of sale pos so you can use this application with clouds hosting online web based for multi device access android iphone windows ios and others or offline desktop based with localhost use a xampp wampp lampp etc.
Donwload open source clean pos point of sale from github extract the file copy on your local host C:/xampp/htdocs/ create new folder rename a pos paste in this folder,open phpmyadmin create a new databased and import databased.sql,now configuration in application/config/config & databased edit and pointing in your databased. open web browser localhost/pos and login with user & pass : admin.
For start this application you can register data in databased menu : user - supplier - categories - produk (with wholesale & retail price),now you can transacation for purchase order - wholesale pos - retail pos - return wholesale, for report you can cek all report in report area just click and view the report.