Frequency Analyzer is a free Android app developed by TadaoYamaoka, falling under the category of Multimedia and the subcategory of Music & Radio. With its high precision, the app calculates the fundamental frequency of a sound with an error rate of less than 0.04%.

The app plots the fundamental frequency versus time, making it an excellent tool for tuning musical instruments. Additionally, the app can be used to measure the sound Doppler effect, as mentioned in the European Journal of Physics. The app's accuracy and versatility make it suitable for both musicians and scientists who require high-precision sound analysis. More information about the app can be found in the reference provided in the app's description.