Amidst rapid diagnostic kits, reverse transcription loop-mediated isothermal amplification (RT-LAMP) has emerged as a rapid point-of-care testing (POCT) method during the COVID-19 pandemic. While many POCT kits rely on plate readers or visual classifications, these processes require experienced staff, and with the use of plate readers, the need for peripheral equipment and infrastructure as well. To address the gap and ensure objectivity in colorimetric POCT kits, the Automated Product Determination (APD) LAMP Diagnostic App was developed for automatic colorimetric analysis of single to multiple LAMP samples. Leveraging on the smartphone camera, barcode-based documentation feature, and a colour distance formula, the app algorithm calculates RGB values, labelling samples as “positive” when yellow, “negative” when pink, and “unknown” when orange. The APD Lamp diagnostic app for Android hereby demonstrates the integration of smartphone apps in POCT kits and ways the smartphone revolution changes laboratory processes to be timely and on-the-go.