There is a variety of audio equalizer apps available for Android, but the one that is most popular and highly rated is Equalizer FX. This app allows you to customize your sound experience by giving you control over the five band equalizer. You can adjust the bands to boost or cut certain frequencies, and save your settings as presets for different types of music. Equalizer FX also includes a bass booster and virtualizer, so you can further tailor your sound.