MusicPhone is an Android composer's notebook application, adapted from MediaPhone (Com-Phone). It's available on the Google Play store as Com-Note, and a simple manual (PDF) is available.
MusicPhone is made available under the terms of the LGPL v3.
Com-Note was adapted from Com-Phone to help composers collaborate and share ideas during the composition process.
For more information about the project, the app's usage and the team behind it, please see the project page.