Competitive gamification in crowdsourcing-based contextual-aware recommender systems

•A mobile crowdsourcing-based context-aware recommender systems (CARS) was developed focusing on the restaurant industry during the COVID-19 outbreak.•A 2-week user study with 68 participants demonstrates that the proposed crowdsourcing-based CARS effectively collects real-time restaurant information and supports users to make dining decisions during epidemics.•According to the post questionnaire, mixed competitive game design encourages both high- and low-performance users to engage more in the crowdsourcing task.•Self-competitive elements motivate both high and low-performance users to take on a wider variety of tasks by the badge-like mechanism with different rewards in each task.