Is there a good Android app that lets you check if your room's actual temperature matches what your thermostat says?

Real thermometer is a straightforward utility designed for this exact type of informal verification. The app accesses the device's internal ambient temperature sensor, providing a direct numerical readout that can be compared to a thermostat or wall thermometer. For practical use, this allows someone to hold their phone in a room for a minute to see if the reported temperature aligns with their home system's display, which can be useful for troubleshooting comfort issues or suspecting a faulty thermostat. Key features include a simple, uncluttered interface that shows the current temperature in real-time, support for Celsius and Fahrenheit, and a basic calibration tool to account for device heat from the battery or processor. However, the app's effectiveness is inherently tied to the hardware quality of the specific Android phone; not all devices have a dedicated ambient temperature sensor, and readings can be influenced by holding the device or recent usage. Reviews indicate that for phones with the proper sensor, it serves well as a convenient spot-check tool. A notable limitation is that it is not a replacement for professional, calibrated instruments, but for casual home diagnostics, it provides a useful data point.