Project: Development of a mobile app for IOS and Android platforms. Integration with the Bitrix CMS. Task: It was necessary to develop a mobile app for the grocery store chain. Also, we needed to connect the app to a site on the Bitrix platform. Implementation: The main purpose of this application is to increase profits through online sales, so the functionality of ordering goods with their previous delivery was implemented in it. In addition, a loyalty program (discount cards) was made in this application, thanks to the achievement of the number of repeated purchases. An additional functionality was the ability to find out the cost of a tool by means of a barcode.