Better mixes start with better mixing skills. Quiztones is a frequency ear-training app that employs unique quiz-based training exercises to teach audio engineers, producers, and musicians to intuitively recognize sounds such as sine waves and pink noise, as well as real-world sounds such as frequency-altered drums, acoustic guitar, electric guitar, bass and vocals—useful skills for mixing, adjusting EQ settings, and identifying/eliminating feedback. The app comes in Mac, iOS and Android versions. The newest version, for Android, is available at an introductory price of $1.99. To learn more about Quiztones, visit quiztones.net.