I just released AnkiDroid 0.4.1, result of the collaboration of about 8 developers and tens of other contributors!
AnkiDroid will always be open source, but it is starting to get attention from companies as well: a Chinese company contributed the Simplified Chinese user interface. This version brings in a lot of new features:
First, the user interface has been translated by volunteers in 13 languages:
- Simplified Chinese
- Traditional Chinese
Second, you can now download decks that have been made by other people. Hundreds of good-quality decks are available in a multitude of topics: sciences, law, languages, medicine, etc.
And lots of other improvements!
In Google's Android Market, search for "Anki".