Airtime Rewards (http://www.airtime.co.uk) offers a mobile app that allows users to earn "connectivity credit" by shopping with over 200 brands, which can be used to reduce their mobile phone bills. The company targets mobile users looking to save on their bills by integrating rewards into their daily shopping habits. The unique selling proposition is the ability to convert everyday purchases into mobile bill credits, making it a practical and rewarding experience for users. This approach redefines traditional rewards systems by providing tangible value through reduced mobile costs.