SimpleChord lets you look up chords and create progressions. Part tool and part toy, it has many uses from teaching music, to providing accompaniment during practice, to quickly sketching songs for work in notation or composition programs.

If you are twitter user you can get this application worth $12.95 for free.

1. Go to the promotional page

2. Click on Write tweet

3. Log in to twitter

4. Tweet the message

5. check the promotional page for the Serial Number.