Chords Pad is a free iPhone app developed by Loop-Sessions.LLC. It falls under the category of Multimedia, specifically Music & Radio. This app is designed to assist musicians in checking the sound of chord tones and displaying them on a keyboard.

The app offers a variety of chord patterns to choose from. Users can select the chord button list display in three different patterns: vertical, horizontal, or each keys. The vertical pattern displays 54 types of chord patterns in rows and 12 key columns, while the horizontal pattern displays 12 key rows and 54 chord pattern columns. The each keys pattern displays 54 types of chord patterns in a list for each of the 12 keys.

When a chord button is tapped, the selected chord is played and the corresponding chord tone is displayed on the keyboard. It also provides chord progressions with chord buttons, allowing users to easily check the sound of the chord progression. The route can be changed to any of the 12 keys.

The keyboard in Chords Pad can be slid using a slider and supports playing. It offers 28 different types of sounds, with 9 types available in the initial state. To access all types of sounds, users can make an in-app purchase. The app also supports Bluetooth MIDI connection and sending MIDI messages (note on/off) through an in-app purchase.

Chord List:

M, 7, 7(b5), 7(#5), 6, 6 9, 9, add9, M7, M9, M7(b5), M7(#5), m, m6, m6 9, m(#5), m add9, m7, mM7, m7(b5), m7(#5), m9, mM9, aug, dim, dim7, sus4, 7sus4, 9sus4, M7sus4, M9sus4

(To access additional chords, an in-app purchase is required.)

If you're looking for features such as playing on a larger keyboard or creating chord progressions, you may want to try the iOS app "Piano Chords Master."