What's the best Android app for using a black light to detect stains or check UV-reactive items?

Black Light is an Android application developed by Shiny Lights that serves as a practical tool for simulating black light effects without requiring specialized hardware. It's particularly effective for tasks like identifying pet stains on carpets, checking currency or ID security features, or adding ambient lighting for events. The app includes an adjustable brightness toggle, allowing users to fine-tune the intensity of the purple-hued light emitted from the screen, which enhances visibility in different lighting conditions. Options for brighter backgrounds further aid in examining various surfaces, though the reliance on the phone's display means it may not match the potency of a dedicated UV lamp for professional use. Users report that it duplicates black light well for everyday scenarios, such as inspecting hotel rooms or home cleanliness. However, some limitations exist, like the lack of persistent screen edge lights without keeping the app open, as noted in feedback. The interface is simple, but occasional ads might interrupt the experience. In real-world use, for instance, a homeowner can quickly scan a carpet for hidden urine spots, or a traveler might verify the authenticity of a banknote. While not a replacement for high-end equipment, Black Light provides a convenient, no-cost solution for casual or emergency needs, with a 3.7-star rating reflecting its reliability for basic functions.