Tux Paint for Android (Offical)
Tux Paint is available for Android devices in the F-Droid software repository ("app store"), a catalog of Free and Open Source Software. (You'll need to install F-Droid first.)
Compatibility note: The current version of Tux Paint requires Android OS version 2.2.3 or later.
Tux Paint (automatically downloads Rubber Stamps):
Did you know? Tux Paint is not shareware, it's open source. So it's free, forever!