A free program for Android, by L-Lingo.

L-Lingo is the ultimate Chinese language learning app for all users. You can use it as a learning tool for daily conversations, as well as for more formal purposes. With L-Lingo, you will be able to learn Chinese in a fun and interactive way. It includes different options for learning the Chinese script, as well as the Latin characters used by many Western countries. It also offers audio files with the pronunciation of the words and sentences, so you will be able to learn the correct pronunciation of the words you want to learn. It is very easy to use and it works on all mobile devices.