It is available for iPhone, iPod, and iPAD. Say you picked addition, then you will see a list of videos: basic addition, Adding 2-digit numbers, … Each video is about 10 to 15 minutes long and very easy to follow. Under Arithmetic, you can choose what you want to work on: addition and subtraction, or Multiplication, or Negative number, etc. For example, under Math, they have Arithmetic. It could be someone who did not quite understand certain concepts during the regular class, thus in need of extra work or someone who wants to get a step ahead. School students at any level (Kindergarten to college), who need additional tutoring on math or science related subjects. Exercises: not available yet, but they say it is coming soon.Track your progress: Log in with your Khan Academy user account to get credit for watching videos, and see your achievements.Subtitles: follow along, skip ahead, or go back by navigating through subtitles.Downloadable videos: take individual teaching videos or entire playlists to watch offline at your own pace.It enables you to view Khan Academy’s complete library of over 2700 videos.

Like their online courses, the app is free. Couple days ago, Khan Academy launched their App. The level of the courses ranges from elementary school to college. The topics include: K-12 math, science (such as biology, chemistry, and physics), finance, history, test prep (GMAT, CAHSEE, SAT math, etc).

It offers free online classes on subjects like math, physics, or history. Khan Academy has become a phenomena in the past couple years.

Khan academy offline