Affordable diagnostic tools and point-of-care diagnostic devices are getting major methodology for health screening at resource-limited-settings. They are implemented and utilized for several challenging problems to facilitate screening and treatment as well as prolonged drug therapies. However, interpretation of test results are still a burden and often biased since no sophisticated computation tools are available. Emerging mobile communication technology provides new opportunities for image processing that evolves interpretation and clinical decision process. We devote our effort to develop functional Apps for smartphones that enable determination of infectious disease at off-field conditions. The early version of BioRGB colorimetric detection application has been utilized screening of HBV and Dengue Fever. Our methodology speeds up screening process and adds value to improve public health.