SyncSpace is a collaborative whiteboard app.
SyncSpace can be used to create drawings and documents on a tablet using free-hand drawing tools, using typing tools, or a combination of the two tool sets.
Drawings and documents can be sent to and synced with other users so that they can comment and edit your drawings and documents.
Download SyncSpace and enjoy it on your iPhone, iPad, and iPod touch. Note iOS 4.2 or later required.
Also available for Android at https://market.android.com/details?id=com.infinitekind.syncspace.android