Answer:
vertical applications software
Step-by-step explanation:
From the question we are informed about Helpers, which is a a nongovernmental organization, launches practbilling, a Web site where all sorts of bills can be paid. It uses a specially designed software to allow hassle-free transactions and charges users a nominal fee. In this case Helpers uses a vertical applications software. Avertical application can be regarded as software which is a defined one, it is
built base on a user's specific requirements so that specific functions and processes can be achieved which user would be considered unique.