In this paper we present the development of Sound Pressure Level Meter and Frequency Spectrum Analyzer application for Android based devices. The developed application can visualize real time waveform and frequency spectrum of an input audio signal in both linear and dB scale. The GPS location, current date and time are also embedded to the application for convenience. A comparison was carried out with currently available smartphone apps of similar type and the results are in good agreement with the app developed in this project. The current version of the app is capable of capturing signal of maximum frequency up to 4000Hz. Therefore, analysis of frequency spectrum of the voice transmission which range between 300Hz to 3400Hz can be carried out successfully.
