ChordPad is described as 'Described as chord sequencer it lets you quickly create chord progressions, play them in many styles, transpose, adjust tempo, change instruments. Great for practicing. I used it for improving my scales on guitar and I have to tell it is amazing' and is an app in the Office & Productivity category. There are seven alternatives to ChordPad for a variety of platforms, including iPhone, iPad, Windows, Mac and Linux. The best alternative is Impro-Visor, which is both free and Open Source. Other great apps like ChordPad are ChordPulse (Freemium), Suggester (Paid), Chord NOTE (Paid) and ChordBud (Paid).
Impro-Visor (short for “Improvisation Advisor”) is a music notation program designed to help jazz musicians compose and hear solos similar to ones that might be improvised. The objective is to improve understanding of solo construction and tune chord changes.
ChordPulse is a handy backing band software for music practice, inspiration, improvisation, and pure fun with music. Play and sing along with ChordPulse. Use it as a full accompaniment, a drum machine with bass, a metronome with chords, and more.
Suggester is a tool to assist in the creation of songs and chord progressions. This app will help you find chords that work together. It is efficient and fun; use it to build musical phrases that will carry emotion through tension and release.