Abstract: Retailers in supermarkets lacks sufficient information at their fingertips when they are in need of determining the placement of products, designing promotion strategies and hence improving the profit of the supermarket and customer satisfaction. This study presents a web based system and an android application required by retailers to make their decision making process more feasible. A set of data items were obtained from a local supermarket and are mined from association rule mining method using Apriori algorithm in order to generate association rules. The system will predict the optimal price of a product using linear regression algorithm, when to host the next product promotion and which product should be promoted. The goal of this research was to design and implement a web based application to view required information on sales predictions and promotion dates in order to make the decision making process effortless for the retailers in supermarkets. A prototype application is designed and implemented using open source tools and technologies.