Willow---I honestly don't know of the reliability of the App because its set up to be as short as 20 questions in 20 minutes and so its probably not the most accurate thing but it is by Mensa the high IQ society and I took it twice in august 2011 and got 101 and 106 which is not much variation so I think its reasonably reliable despite being shorter. Also Mensa actually gives IQ tests routinely so you can join so I'm under the assumption that they know how to test it. I've also done some of the free on-line ones as well and they are comparable. Anyway the splash screen for the app says american mensa brain test I have it on the iphone I have no idea if it exists on other platforms.