Rayyan is a free web and mobile application designed to streamline the initial screening of abstracts and titles in systematic reviews. Developed by researchers at Qatar Computing Research Institute and Cochrane Bahrain, Rayyan aims to improve the efficiency and accuracy of the systematic review process by incorporating semi-automation and user-friendly features. The app allows users to filter and manage citations, collaborate on reviews, and use predictive features to assist in the screening process. The app was tested using two published Cochrane reviews, with results showing significant time savings for users. On average, users reported a 40% time saving when using Rayyan compared to other tools, with 34% reporting more than 50% time savings. Around 75% of users identified screening and labeling studies as the two most important features of Rayyan. The app's ability to help with screening and collaboration was highlighted as a key strength. Rayyan is built on a cloud-based architecture, allowing it to scale efficiently and handle a large number of users and citations. It supports various citation formats and provides features such as similarity graphs, keyword filtering, and real-time notifications. The app also includes a prediction feature that learns from user decisions to include or exclude studies, improving the accuracy of future predictions. Rayyan has been widely adopted, with over 2000 users from more than 60 countries conducting hundreds of reviews on over 1.6 million citations. User feedback has highlighted the app's ease of use, time savings, and ability to facilitate collaboration. The developers have continuously improved the app based on user feedback, incorporating new features such as text highlighting, blinded selection, and automatic data extraction. Future developments aim to enhance Rayyan's capabilities, including better duplicate detection, risk of bias assessment, and integration with other software platforms. Rayyan is available for free at http://rayyan.qcri.org and is fully funded by the Qatar Foundation. The app has shown significant potential to reduce the workload of systematic review authors by speeding up the screening process and improving the efficiency of the review process.Rayyan is a free web and mobile application designed to streamline the initial screening of abstracts and titles in systematic reviews. Developed by researchers at Qatar Computing Research Institute and Cochrane Bahrain, Rayyan aims to improve the efficiency and accuracy of the systematic review process by incorporating semi-automation and user-friendly features. The app allows users to filter and manage citations, collaborate on reviews, and use predictive features to assist in the screening process. The app was tested using two published Cochrane reviews, with results showing significant time savings for users. On average, users reported a 40% time saving when using Rayyan compared to other tools, with 34% reporting more than 50% time savings. Around 75% of users identified screening and labeling studies as the two most important features of Rayyan. The app's ability to help with screening and collaboration was highlighted as a key strength. Rayyan is built on a cloud-based architecture, allowing it to scale efficiently and handle a large number of users and citations. It supports various citation formats and provides features such as similarity graphs, keyword filtering, and real-time notifications. The app also includes a prediction feature that learns from user decisions to include or exclude studies, improving the accuracy of future predictions. Rayyan has been widely adopted, with over 2000 users from more than 60 countries conducting hundreds of reviews on over 1.6 million citations. User feedback has highlighted the app's ease of use, time savings, and ability to facilitate collaboration. The developers have continuously improved the app based on user feedback, incorporating new features such as text highlighting, blinded selection, and automatic data extraction. Future developments aim to enhance Rayyan's capabilities, including better duplicate detection, risk of bias assessment, and integration with other software platforms. Rayyan is available for free at http://rayyan.qcri.org and is fully funded by the Qatar Foundation. The app has shown significant potential to reduce the workload of systematic review authors by speeding up the screening process and improving the efficiency of the review process.