One you've studied Test Mode replicates the actual test conditions, requiring you to answer 50 questions in 50 minutes. At the end of Test Mode your final score is shown, letting you know whether your percentage would be enough for you to pass or fail the official test. The app will also show your best and worst scoring categories, so you know where to concentrate your future revision efforts.
For learner drivers the alternative to downloading the AA Theory Test app is buying one of the paper book alternatives. While books do, arguably, provide an easier to use study guide (work through any question you want at any time), they aren't able to simulate test conditions in the same way that the app can. Moreover, the app is about one fifth of the price of the typical theory test study book, making it excellent value for money.
Windows Phone description:
Become a safer driver and prepare for your theory test using your Windows Phone!
The Theory Test application by the AA enables you to prepare for your theory test by allowing you to practice the official Driving Standards Agency (DSA) questions and even take a test which is designed to be just like the real test situation!
AA Theory Test can be downloaded from the Windows Phone Store. A free trial is available, with the full app costing £1.99.