12th graders at the iTunes store the other day and downloaded it.
First I'll say that this app and the other apps are free and advertised to be based on the Common Core. This app has over 350 questions in 6 strands that a student can work through or can focus on a single strand.
If a student wants to work on a specific strand, they click on the drop down menu to select the strand and those question classified as being part of the strand remain while the others disappear. It turns out the strands are in order so the first 20 are Arithmetic, the second 40 might be Algebra, etc.
Each question comes with a picture and four possible answers so the student gets practice with multiple choice questions.
The student selects the answer and they get immediate feedback on the correctness of their answer. If their choice is correct, a green stripe appears on their answer, if its wrong, they see a red stripe. In addition, the app provides a solution even if the student gets the answer correct. The solution includes an explanation of the math behind the problem.
The best thing about this app is that you do not need an internet connection to use it but the questions never change so its easy to memorize the answer and do well. On the other hand, some of these questions are quite challenging and most students will not be able to rush through the app.
They also have a web site students can use rather than downloading the app on the iPad. It has the same material as the apps with the same questions and formats.