Features:
- difficulty level information in each question.
- automatic adjustment on difficulty level based on usage statistics.
- 3 standards test mode based on difficulty level: easy (for beginner), medium, difficult(for expert).
- 1 adaptive test mode.
- Hall of Fame, compare your score (knowledge) with other people.
- Review latest test for incorrect answer (available on limited version)

NOTES:
- Test Materials are submitted by users around the world. If you find problem with test material, please contribute by informing correction, submitting new material, etc.

PERMISSIONS EXPLAINED:
- Internet Access: for data synchronization and ads
- Coarse Location: to notify you if you are in the country where we have other app version (e.g. full version), usually under coverage of certain operator
- Discover Known Account: to automatically put your name when you want to post your score in our hall of fame (you can still skip posting the score or change your name).
- Read phone state and identify: to protect our test content in the device from piracy. no personal sensitive personal information is taken. (see http://www.androidcentral.com/look-application-permissions)