In this review, we explore the potential of smartphoneâbased applications based on their unique ability to support portable, easyâtoâuse, precise, and efficient functions, which, in turn, makes labâonâhardware a trending area of novel research. Smartphones can assist surgeons, physicians, biologists, chemists, ophthalmologists, and laboratory technicians in maintaining an easyâtoâuse, costâeffective, and integrated environment for treatment, diagnosis, and pointâofâcare (POC) applications. These POC applications can improve patients' quality of life, offering patients a precise diagnosis and the correct treatment. This is a noble goal that aims to reduce costs and to increase the accuracy of sample testing, treatment, and diagnosis. Recent innovations have made major advances in smartphone adapters, providing portability, robustness, selfâpowered devices, smallâsized adapters, and ease of usage. Labâonâhardware is a progressing field, and smartphone imaging applications are increasingly expanding, resulting in POC applications with the latest and most advanced image analysis, enhancement, recognition, and other image processing techniques. The most recent studies in the field are explored to provide a solid background to interested researchers against which they can choose of application and/or adapter design they aim to develop, with a discussion of the methods reviewed here.