The Music Maestro is a music theory utility app that I accepted a contract from Music Maestro, Inc. to develop concurrently for iPad and Android tablets. It was developed in both Java and Objective-C using Android / Eclipse and iOS / Xcode.
The Music Maestro is a simple-to-use tool that illustrates the notes used to construct major, minor, pentatonic, and blues scales, as well as major, minor, seventh, and minor seventh chords on guitar and keyboard. This app also illustrates the correct chords that are played in a particular scale.
The Music Maestro has been temporarily removed from the Google Play Store and App Store at the discretion of Music Maestro, Inc. Source code is proprietary, but live demos are available upon request.